View source for Ambigram

{{Short description|Symmetrical calligraphic or typographic visual pun}}
[[File:Ambigram of the word ambigram - rotation animation.gif|thumb|Animation of a half-turn ambigram of the word ''ambigram'', with 180-degree rotational symmetry<ref name="QuantaMagazine">{{Cite web|website=[[Quanta Magazine]]|title=New Clues About 'Ambigram' Viruses With Strange Reversible Genes|first=Jordana|last=Cepelewicz|language=en|date=2020-02-12 |url=https://www.quantamagazine.org/new-clues-about-ambigram-viruses-with-strange-reversible-genes-20200212/ |archive-url=https://web.archive.org/web/20210917150142/https://www.quantamagazine.org/new-clues-about-ambigram-viruses-with-strange-reversible-genes-20200212/ |archive-date=2021-09-17 |access-date=17 November 2021}}</ref>]]
An '''ambigram''' is a [[calligraphic]] composition of [[glyph]]s (letters, numbers, symbols or other shapes) that can yield different meanings depending on the orientation of observation.<ref name="AmbigramMeriamWebster" /><ref name="EuronewsScrabble" /> Most ambigrams are visual [[palindrome]]s that rely on some kind of [[symmetry]], and they can often be interpreted as [[visual pun]]s.<ref name="polster" /> The term was coined by [[Douglas Hofstadter]] in 1983–1984.<ref name="AmbigramMeriamWebster" /><ref name="HofstadterIndiana" />

Most often, ambigrams appear as visually symmetrical words. When flipped, they remain unchanged, or they mutate to reveal another [[Semantics|meaning]]. "Half-turn" ambigrams undergo a [[point reflection]] (180-degree [[rotational symmetry]]) and can be read upside down (for example, the word "swims"), while mirror ambigrams have [[axial symmetry]] and can be read through a [[reflective]] surface like a [[mirror]]. Many other types of ambigrams exist.<ref name="OxfordEnglishDictionary">{{cite web |title=Ambigram |url=https://www.oed.com/search/dictionary/?scope=Entries&q=ambigram |archive-url=https://web.archive.org/web/20230725014028/https://www.oed.com/search/dictionary/?scope=Entries&q=ambigram&tl=true |archive-date=2023-07-25 | website=[[Oxford English Dictionary]]|language=en |access-date=2023-07-25}}</ref>

Ambigrams can be constructed in various [[Written language|languages]] and [[alphabet]]s, and the notion often extends to [[numbers]] and other [[symbol]]s. It is a recent [[interdisciplinary]] concept, combining [[Visual arts|art]], [[literature]], [[mathematics]], [[cognition]], and [[optical illusions]]. Drawing symmetrical words constitutes also a [[recreational activity]] for [[amateur]]s. Numerous ambigram [[logo]]s are famous, and ambigram [[tattoo]]s have become increasingly popular. There are methods to design an ambigram, a field in which some [[artist]]s have become specialists.

==Etymology==

The word ''ambigram'' was coined in 1983 by [[Douglas Hofstadter]], an American scholar of [[cognitive science]] best known as the [[Pulitzer Prize]]-winning author of the book ''[[Gödel, Escher, Bach]]''.<ref name="SunJournalWow">{{cite news |last=Witherellspecial |first=Jim |date=2022-02-27 |title=In a word: Wow, the many ways words are symmetrical |url=https://www.sunjournal.com/2022/02/27/in-a-word-wow-the-many-ways-words-are-symmetrical/ |work=[[Sun Journal (Lewiston, Maine)|Sun Journal]] |location=[[Maine]] |access-date=2022-12-06 |url-status=live |archive-url=https://web.archive.org/web/20220504210847/https://www.sunjournal.com/2022/02/27/in-a-word-wow-the-many-ways-words-are-symmetrical/ |archive-date=2022-05-04}}</ref><ref name="polster">{{Cite web|url=https://www.qedcat.com/articles/ambigram.pdf|title=Mathemagical Ambigrams|last=Polster|first=Burkard|language=en|access-date=2020-03-29|archive-url=https://web.archive.org/web/20230705071120/https://www.qedcat.com/articles/ambigram.pdf|archive-date=2023-07-05}}</ref><ref name="HofstadterIndiana">{{Cite web|title=Douglas R. Hofstadter|url=https://newsinfo.iu.edu/news-archive/5075.html|date=2007-03-21|access-date=2021-08-07|website=[[Indiana University Bloomington|Indiana University]]|language=en}}</ref>
It is a [[neologism]] composed of the Latin prefix [[wikt:ambi-|ambi-]] ("both") and the Greek suffix [[wikt:-gram|-gram]] ("drawing, writing").<ref name="AmbigramMeriamWebster" />

Hofstadter describes ambigrams as "calligraphic designs that manage to squeeze in two different readings."<ref name="Adobe">{{Cite web|title=Deciphering the art of ambigrams|url=https://www.adobe.com/creativecloud/design/discover/ambigram.html|access-date=2021-08-08|website=Adobe|language=en}}</ref> "The essence is imbuing a single [[calligraphy|written form]] with [[ambiguity]]".<ref name="MetamagicalThemas" /><ref name="MetamagicalThemasPage37">{{Cite book|title=Metamagical Themas: Questing For The Essence Of Mind And Pattern|url=https://readfrom.net/douglas-hofstadter/page,37,516732-metamagical_themas.html|archiveurl=https://web.archive.org/web/20230905021853/https://readfrom.net/douglas-hofstadter/page,37,516732-metamagical_themas.html|archivedate=2023-09-05|last=Hofstadter|first=Douglas|isbn=978-0-7867-2386-7|publisher=Basic Books|year=2008|pages=880|quote-page=37|language=en}}</ref>

{{Blockquote
|text=An ''ambigram'' is a [[visual pun]] of a special kind: a [[calligraphy|calligraphic design]] having two or more (clear) [[Interpretation (philosophy)|interpretations]] as [[written word]]s. One can voluntarily jump back and forth between the rival [[readings]] usually by shifting one's physical [[Perspective (visual)|point of view]] (moving the design in some way) but sometimes by simply altering one's [[perceptual]] bias towards a design (clicking an internal mental switch, so to speak). Sometimes the readings will say identical things, sometimes they will say different things.<ref name="Hofstadter1987">{{harvsp|Hofstadter|1987}}.</ref><ref name="polster" />
|author=[[Douglas Hofstadter]]
}}

Hofstadter attributes the origin of the word ''ambigram'' to conversations among a small group of friends in 1983.<ref name="harvsp|Polster|2007|p=198">{{harvsp|Polster|2007|p=198}}.</ref>

Prior to Hofstadter's [[terminology]], other names were used to refer to ambigrams. Among them, the expressions "vertical [[palindrome]]s"<ref name="PotentialPlusUK">{{Cite web|title=Are You an Oulipian?|url=https://potentialplusuk.org/index.php/2018/05/16/are-you-an-oulipian/|website=[[Potential Plus UK]]|location=[[Milton Keynes]]|language=en|date=2022-11-16|archive-url=https://web.archive.org/web/20220125162931/https://potentialplusuk.org/index.php/2018/05/16/are-you-an-oulipian/|archive-date=2022-01-25|access-date=2023-10-30}}</ref> by [[Dmitri Borgmann]]<ref>{{cite book|last=Borgmann |first=Dmitri |author-link=Dmitri Borgmann |title=[[Language on Vacation: An Olio of Orthographical Oddities]]  |publisher=Scribner |year=1965 |asin=B0007FH4IE|page=27}}</ref> (1965) and [[Georges Perec]],<ref name="PerecLiberation">{{Cite web|title=L'écrit touareg du sable au papier. Un typographe français a retranscrit l'alphabet des hommes du désert.|url=https://www.liberation.fr/culture/1996/07/27/l-ecrit-touareg-du-sable-au-papierun-typographe-francais-a-retranscrit-l-alphabet-des-hommes-du-dese_176184/|date=1996-07-27|access-date=2021-08-10|website=Liberation|language=fr}}</ref><ref name="PerecAPMEP">{{Cite web|title=Ce repère, Perec.|url=https://www.apmep.fr/IMG/pdf/Aja15_Perec.pdf|access-date=2021-08-07|website=APMEP (Association des Professeurs de Mathématiques de l'Enseignement Public)|language=fr}}</ref> "designatures" (1979),<ref>OMNI magazine, September 1979, page 143, work of Scott Kim</ref> "inversions" (1980) by [[Scott Kim]],<ref name="Kim1986">{{harvsp|Kim|1986}}.</ref><ref>{{harvsp|Prokhorov|2013|p=25}}.</ref> or simply "upside-down words" by [[John Langdon (typographer)|John Langdon]] and Robert Petrick.<ref>{{harvsp|Prokhorov|2013|p=18}}.</ref>

''Ambigram'' was added to the [[Oxford English Dictionary]] in March 2011,<ref name="OxfordEnglishDictionary" /><ref name="OxfordUpdate">{{cite web |title=Latest update March 2011 (List of new words) |url=http://www.oed.com |archive-url=https://web.archive.org/web/20110410100508/http://www.oed.com//public//latest//latest-update//#new |archive-date=2011-04-10 | website=[[Oxford English Dictionary]]|language=en |access-date=2021-08-28}}</ref> and to the [[Merriam-Webster]] dictionary in September 2020.<ref name="AmbigramMeriamWebster">{{cite web |title=Definition of ambigram |url=https://www.merriam-webster.com/dictionary/ambigram |website=[[Merriam-Webster]] | language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20200915200524/https://www.merriam-webster.com/dictionary/ambigram |archive-date= 2020-09-15}}.</ref><ref name="Merriam-WebsterNewWord">{{cite web |title=Words We're Watching: 'Ambigram' |url=https://www.merriam-webster.com/words-at-play/words-were-watching-ambigram |website=[[Merriam-Webster]] | language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210923100805/https://www.merriam-webster.com/words-at-play/words-were-watching-ambigram |archive-date= 2021-09-23}}.</ref> [[Scrabble]] included the word in its database in November 2022.<ref name="CNN-Scrabble">{{cite news |last=Scottie |first=Andrew |date=2022-11-16 |title=Scrabble adds 500 new playable words, like 'vax,' 'deepfake' and 'Jedi' |url=https://edition.cnn.com/2022/11/16/us/scrabble-new-words-bae-guac-vax-cec/index.html |work=[[CNN]] |location=[[Atlanta]] |access-date=2022-12-06 |url-status=live |archive-url=https://web.archive.org/web/20221120041248/https://edition.cnn.com/2022/11/16/us/scrabble-new-words-bae-guac-vax-cec/index.html |archive-date=2022-11-20}}</ref><ref name="EuronewsScrabble">{{cite news |last=Mouriquand |first=David |date=2022-11-18 |title=Scrabble adds 500 new words to its official dictionary |url=https://www.euronews.com/culture/2022/11/18/scrabble-adds-500-new-words-to-its-official-dictionary |work=[[Euronews]] |location=[[Lyon]] |access-date=2022-12-06 |url-status=live |archive-url=https://web.archive.org/web/20221124181715/https://www.euronews.com/culture/2022/11/18/scrabble-adds-500-new-words-to-its-official-dictionary |archive-date=2022-11-24}}</ref><ref name="MerriamWebsterScrabble">{{cite web |date=2022-11-16 |title=Words Added to the Scrabble Dictionary |author=<!--Not stated--> |url=https://www.merriam-webster.com/words-at-play/words-added-to-the-scrabble-dictionary |website=[[Merriam-Webster]] |location=[[Springfield, Massachusetts]] |access-date=2022-12-06 |url-status=live |archive-url=https://web.archive.org/web/20221205010739/https://www.merriam-webster.com/words-at-play/words-added-to-the-scrabble-dictionary |archive-date=2022-12-05}}</ref>

==History==

[[File:Sator_Square_at_Oppède.jpg|thumb|[[Sator square]] ([[word square]] and [[palindrome]]) with the letters S and N reversed.]]

[[File:Ambigram_-_puzzle_-_the_end_-_by_Peter_Newell_1893_-_book_Topsys_and_turvys_(crop).jpg|thumb|Rotational ambigram ''Puzzle / The end'' by [[Peter Newell]] designed in 1893.]]

[[File:Ambigram_palindrome_ΝΙΨΟΝΑΝΟΜΗΜΑΤΑΜΗΜΟΝΑΝΟΨΙΝ_(Wash_your_sins,_not_only_your_face,_in_Greek).jpg|thumb|left|[[Mirror image|Mirror]] ambigram ΝΙΨΟΝ ΑΝΟΜΗΜΑΤΑ ΜΗ ΜΟΝΑΝ ΟΨΙΝ ([[Nipson anomemata me monan opsin|''Wash your sins, not only your face'']], in [[Ancient Greek]]) in the {{ill|monastery Panagia Malevi|lt=''monastery Panagia Malevi''|el|Μονή Μαλεβής Αρκαδίας}}.<ref name="Dinfo">{{Cite web|title=Παναγία Μαλεβή: Το Άγιο Όρος της Πελοποννήσου|url=https://www.dinfo.gr/%CF%80%CE%B1%CE%BD%CE%B1%CE%B3%CE%AF%CE%B1-%CE%BC%CE%B1%CE%BB%CE%B5%CE%B2%CE%AE-%CF%84%CE%BF-%CE%AC%CE%B3%CE%B9%CE%BF-%CF%8C%CF%81%CE%BF%CF%82-%CF%84%CE%B7%CF%82-%CF%80%CE%B5%CE%BB%CE%BF%CF%80%CE%BF/|website=Dinfo.gr|language=el|archive-url=https://web.archive.org/web/20231115024050/https://www.dinfo.gr/%CF%80%CE%B1%CE%BD%CE%B1%CE%B3%CE%AF%CE%B1-%CE%BC%CE%B1%CE%BB%CE%B5%CE%B2%CE%AE-%CF%84%CE%BF-%CE%AC%CE%B3%CE%B9%CE%BF-%CF%8C%CF%81%CE%BF%CF%82-%CF%84%CE%B7%CF%82-%CF%80%CE%B5%CE%BB%CE%BF%CF%80%CE%BF/|archive-date=2023-11-15|access-date=2023-11-15}}</ref>]]

[[File:Ambigrams_Chump,_honey,_M._H._Hill,_Bet,_and_five_more_words_-_Strand_Magazine_1908.jpg|thumb|Ambigrams published in ''[[The Strand Magazine]]'', June 1908.]]

Many ambigrams can be described as [[graphic]] [[palindromes]].

The first [[Sator square]] palindrome was found in the ruins of [[Pompeii]], meaning it was created before the [[Eruption of Mount Vesuvius in 79 AD]].
A sator square using the [[mirror writing]] for the representation of the letters S and N was carved in a stone wall in [[Oppède]] (France) between the [[Roman Empire]] and the [[Middle Ages]],<ref name="Oppede">{{Cite web|title=Menerbes|url=https://www.lydieshouse.com/fr/visit-provence/beautiful-villages/menerbes/|access-date=2021-08-07|website=Lydie's House|language=fr}}</ref> thus producing a work made up of 25 letters and 8 different [[Character (symbol)|characters]], 3 naturally symmetrical (A, T, O), 3 others decipherable from left to right (R, P, E), and 2 others from right to left (S, N). This engraving is therefore readable in four directions.<ref name="TenetVox">{{cite web |title=The ancient palindrome that explains Christopher Nolan's Tenet |url=https://www.vox.com/culture/21419050/tenet-explained-sator-square-nolan |website=[[Vox (website)|Vox]] |date =2020-09-04 |language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210829181034/https://www.vox.com/culture/21419050/tenet-explained-sator-square-nolan |archive-date= 2021-08-29}}.</ref>

Although the term is recent, the existence of [[Mirror image|mirror]] ambigrams has been attested since at least the [[first millennium]]. They are generally [[palindromes]] [[stylized]] to be visually [[symmetrical]].

In [[ancient Greek]], the phrase {{lang|grc-x-byzant|[[Nipson anomemata me monan opsin|"ΝΙΨΟΝ ΑΝΟΜΗΜΑΤΑ ΜΗ ΜΟΝΑΝ ΟΨΙΝ"]]}} (''wash the sins, not only the face''), is a [[palindrome]] found in several locations, including the site of the church [[Hagia Sophia]] in Turkey.<ref name="HagiaSophia">R. Langford-James, ''A Dictionary of the Eastern Orthodox Church'', Ayer Publishing, {{ISBN|978-0-8337-5047-1}}, p. 61.</ref><ref name="SecretLanguage">Barry J. Blake, ''Secret Language: Codes, Tricks, Spies, Thieves, and Symbols'', Oxford University Press, 2010, {{ISBN|978-0-19-957928-0}}, p. 15.</ref> It is sometimes turned into a mirror ambigram when written in capital letters with the removal of [[Space (punctuation)|spaces]], and the stylization of the letter Ν (<span style="{{mirrorH}}">Ν</span>).

A [[boustrophedon]] is a type of [[bi-directional text]], mostly seen in ancient manuscripts and other inscriptions. Every other line of writing is flipped or reversed, with reversed letters. Rather than going left-to-right as in modern European languages, or right-to-left as in [[Arabic]] and [[Hebrew]], alternate lines in boustrophedon must be read in opposite directions. Also, the individual characters are reversed, or mirrored. This two-way writing system reveals that modern ambigrams can have quite ancient origins, with an intuitive component in some minds.

Mirror writing in [[Islamic calligraphy]] flourished during the early modern period, but its origins may stretch as far back as pre-Islamic mirror-image rock inscriptions in the [[Hejaz]].<ref name="Crosbi">{{Cite web|title=Islamic Calligraphy and Visions|url=https://www.bib.irb.hr/754176/download/754176.Islamic_Calligraphy_and_Visions.pdf|access-date=2021-08-07|website=Crosbi|language=en|archive-date=2023-07-05|archive-url=https://web.archive.org/web/20230705071122/https://www.bib.irb.hr/754176/download/754176.Islamic_Calligraphy_and_Visions.pdf|url-status=bot: unknown}}</ref>

The earliest known non-natural [[Point reflection|rotational]] ambigram dates to 1893 by artist [[Peter Newell]].<ref name="Topsys">{{Cite web|title=Topsys & turvys|url=https://www.loc.gov/item/16005309/|access-date=2021-08-07|website=Library of Congress|language=en}}</ref> Although better known for his children's books and illustrations for [[Mark Twain]] and [[Lewis Carroll]], he published two books of [[reversible figure|reversible illustrations]], in which the picture turns into a different image entirely when flipped [[Point reflection|upside down]]. The last page in his book ''Topsys & Turvys'' contains the phrase ''The end'', which, when inverted, reads ''Puzzle''. In ''Topsys & Turvys Number 2'' (1902), Newell ended with a variation on the ambigram in which ''The end'' changes into ''Puzzle 2''.<ref>{{harvsp|Polster|2007|p=6}}.</ref>

In March 1904 the Dutch-American [[comic]] artist [[Gustave Verbeek]] used ambigrams in three consecutive strips of ''The UpsideDowns of old man Muffaroo and little lady Lovekins''.<ref name="Sunday Press">{{cite book |last1=Verbeek |first1=Gustave |title=The Upside-Down World of Gustave Verbeek |date=2009 |publisher=Sunday Press |isbn=978-0-9768885-7-4}}</ref> His comics were [[ambiguous image]]s, made in such a way that one could read the six-panel comic, flip the book and keep reading.

From June to September 1908, the British monthly ''[[The Strand Magazine]]'' published a series of ambigrams by different people in its "[[Cabinet of curiosities|Curiosities]]" column.<ref name="TheStrandMagazinePage359">{{Cite magazine|last=Newnes|first=George|date=1908|title=Curiosities|url=https://books.google.com/books?id=45MkAQAAIAAJ&q=Possibly+B+is+the+only+letter+of+the+alphabet+that+will+produce+such+an+interesting+anomaly&pg=PA359|magazine=The Strand Magazine|issue=36|page=359|access-date=6 November 2016}}</ref> Of particular interest is the fact that all four of the people submitting ambigrams believed them to be a rare property of particular words. Mitchell T. Lavin, whose "chump" was published in June, wrote, "I think it is in the only word in the English language which has this peculiarity," while Clarence Williams wrote, about his "Bet" ambigram, "Possibly B is the only letter of the alphabet that will produce such an interesting anomaly."<ref name="TheStrandMagazinePage359" /><ref>[[:File:Ambigrams Chump, honey, M. H. Hill, Bet, and five more words - Strand Magazine 1908.jpg|Ambigrams Chump, honey, M. H. Hill, Bet, and five more words – ''Strand Magazine'' 1908]]</ref>

==Characteristics==

===Natural ambigrams===

[[File:SOS_Italian_traffic_signs_in_2020.05.jpg|thumb|upright|left|The distress signal [[SOS]] is a natural rotating ambigram.]]

[[File:Ambigram_OHIO_(90_degrees_rotational_symmetry_-_animated).gif|thumb|"Quarter-turn" natural ambigram]]

[[File:619sign.JPG|thumb|The [[619 (number)|number 619]] constitutes a natural ambigram (but not the word "western").]]

In the [[Latin alphabet]], many letters are symmetrical [[glyph]]s. The [[capital letters]] B, C, D, E, H, I, K, O, and X have a horizontal symmetry axis. This means that all words that can be written using only these letters are natural [[Reflection (physics)|lake reflection]] ambigrams; examples include BOOK, CHOICE, or DECIDE.

The [[lowercase]] letters o, s, x, and z are [[rotationally symmetric]], while pairs such as b/q, d/p, n/u, and in some [[typeface]]s a/e, h/y and m/w, are rotations of each other. Among the lowercase letters "l" is unique since its symmetry is broken if it is close to a reference character which establishes a clear [[x-height]]. When rotated around the middle of the x-height l/ȷ or lo/oȷ it doesn't appear the same, but it does when rotated around its center like the uppercase-I. Thus, the words "sos", "pod", "suns", "yeah", "swims", "passed", or "dollop",<!--Please keep the list reasonably short--> form natural rotational ambigrams.

More generally, a "natural ambigram" is a word that possesses one or more [[symmetries]] when written in its natural state, requiring no [[typographic]] [[Style (visual arts)|styling]]. The words "bud", "bid", or "mom", form natural mirror ambigrams when reflected over a [[axial symmetry|vertical axis]], as does "[[wikt:ليبيا#Arabic|ليبيا]]", the name of the country [[Libya]] in [[Arabic]]. The words "HIM", "TOY, "TOOTH" or "MAXIMUM", in all capitals, form natural mirror ambigrams when their letters are stacked vertically and reflected over a vertical axis. The [[uppercase]] word "[[Ohio|OHIO]]" can flip a quarter to produce a 90° [[Rotational symmetry|rotational]] ambigram when written in [[serif]] style (with large "feet" above and below the "I").

Like all [[strobogrammatic number]]s, [[69 (number)|69]] is a natural rotational ambigram.

[[Patterns in nature]] are regularities found in the natural world.<ref name="Nature">{{cite journal |first1=Joseph L. |last1=DeRisi |first2=Greg |last2=Huber |first3=Amy |last3=Kistler |first4=Hanna |last4=Retallack |first5=Michael |last5=Wilkinson |first6=David |last6=Yllanes |date=2019-11-29 |title=An exploration of ambigrammatic sequences in narnaviruses |journal=[[Nature (journal)|Nature]] |volume=9 |issue=1 |page=17982 |article-number=17982 |doi=10.1038/s41598-019-54181-3 |pmid=31784609 |pmc=6884476 |bibcode=2019NatSR...917982D |s2cid=202854658 }}</ref> Similarly, [[patterns]] in ambigrams are regularities found in [[grapheme]]s.
As a consequence to this "natural" property, some [[shapes]] appear more or less appropriate to handle for the [[calligrapher|designer]]. Ambigram candidates can become "''almost'' natural", when all the letters except maybe one or two are symmetrically cooperative, for example the word "awesome" possesses 5 compatible letters (the central s that flips around itself, and the couples a/e and w/m).

===Single word or several words===
A symmetrical ambigram can be called "homogram" (contraction of "homo-ambigram") when it remains unchanged after reflection, and "heterogram" when it transforms.<ref name="Hofstadter1987" /><ref name="Semiotik">{{Cite book|url=https://books.google.com/books?id=FRPGhaP0mnEC&pg=PA3588|title=Semiotik Semiotics|last=de Gruyter|first=Walter|publisher=Herbert Ernst Wiegand|year=2004|page=3588|isbn=978-3-11-017962-0|language=en}}</ref> In the most common type of ambigram, the two [[Language interpretation|interpretations]] arise when the image is rotated 180 degrees with respect to each other (in other words, a second reading is obtained from the first by simply rotating the sheet).

====Single====

[[Douglas Hofstadter]] coined the word "homogram" to define an ambigram with identical letters.<ref name="Hofstadter1987" /><ref name="Semiotik" /> In this case, the first half of the word turns into the last half.<ref name="Prokhorov2013">{{harvsp|Prokhorov|2013}}.</ref>

<gallery mode="packed" class="center">
Wikipedia-ambigram.svg|Ambigram "[[Wikipedia]]", drawn by French artist [[Jean-Claude Pertuzé]], 180° rotational symmetry.
Ambigram_Candy_icon_-_pink_animated.gif|"[[Candy]]", 180° symmetrical ambigram.
Ambigram_Cloud_-_blue.png|"[[Cloud]]", vertical axis mirror ambigram with a cloud occupying [[negative space]] in the letter O.
Ambigram Doug - white on black animated.gif|"Doug", [[hypocorism]] for [[Douglas Hofstadter]], the "father" of the ambigram concept.
</gallery>

====Several====

[[File:Ambigram_India_and_Nepal_-_gray_and_beige.svg|thumb|Three word ambigram: a changing combination "[[India]] / [[Nepal]]" associated with the invariant conjunction "and".]]

A symmetrical ambigram may be called a "heterogram"<ref name="Hofstadter1987" /><ref name="Semiotik" /> (contraction of "hetero-ambigram") when it becomes a different word after rotation. Visually, a hetero-ambigram is symmetrical only when both versions of the pairing are shown together. The [[aesthetic]] appearance is more difficult to design when a changing ambigram is intended to be shown in one way only, because [[Symmetry#In the arts|symmetry]] generally enhances the visual appearance of artwork. Technically, there are two times more combinations of letters involved in a ''hetero-ambigram'' than in a ''homo-ambigram''. For example, the 180° rotational ambigram "yeah" contains only two pairs of letters: y/h and e/a, whereas the heterogram "yeah / good" contains four : y/d, e/o, a/o, and h/g.

There is no limitation to the number of words that can potentially be paired up as hetero-ambigrams, and full ambigram [[Sentence (linguistics)|sentences]] have even been published.<ref name="PerecLiberation" /><ref name="Prokhorov2013" />

<gallery mode="packed" class="center">
File:Ambigram Ambigram Wikipedia (animated).gif|"Ambigram / [[Wikipedia]]", ''hetero-'' type.<ref>{{cite book|first= Bertrand|last= Cloez|title=Recueil de curiosités mathématiques|publisher= [[:fr:Éditions Ellipses|Éditions Ellipses]]|date=2022-03-22|page=51|url=https://books.google.com/books?id=MillEAAAQBAJ&pg=PA51|archive-url=https://web.archive.org/web/20221116075222/https://books.google.com/books?id=MillEAAAQBAJ&pg=PA51|archive-date=2022-11-16|access-date=17 November 2022|language=fr|isbn=978-2-340-06713-4}}</ref>
File:Ambigram_true_flag.png|"True flag", [[self-referential]] flag, horizontal axis mirror ''hetero-'' type.
File:Ambigram Stay here (animated).gif|Two word ambigram "Stay Here".
File:Ambigram_Real_Fake_animated_(1).gif|Two word ambigram "[[Reality|Real]] / [[Illusion|Fake]]" showing alternatively one version of the pair.
</gallery>

==Types==

Ambigrams are exercises in [[graphic design]] that play with [[optical illusion]]s, [[symmetry]] and [[visual perception]].
Some ambigrams feature a relationship between their [[Visual appearance|form]] and their [[Semantics|content]]. Ambigrams usually fall into one of several categories.

===180° rotational===

[[File:Ambigram_Upside_Down_-_animation.gif|thumb|180° rotational ambigram saying "Upside Down".<ref name="NazarethCollege"/>]]

"Half-turn" ambigrams or ''[[point reflection]]'' ambigrams, commonly called "upside-down words", are 180° [[rotational symmetry|rotational symmetrical]] [[calligraphies]].<ref name="SunJournalWow" /> They can be read right side up or upside down, or both.

{{Blockquote
|text=Rotation ambigrams are the most common type of ambigrams for good reason. When a word is [[point reflection|turned upside down]], the top halves of the letters turn into the bottom halves.
And because our eyes pay attention primarily to the top halves of letters when we read, that means that you can essentially chop off the top half of a word, turn it upside down, and glue it to itself to make an ambigram. [...]<ref>{{harvsp|Prokhorov|2013|p=29}}.</ref>
|author=[[Scott Kim]]
}}

<gallery mode="packed" class="center">
File:Ambigram Say Yes radial pattern rainbow color - rotation animation.gif|Rotating ambigram "Say Yes", half-turn type with 8 occurrences of the same [[pattern]]. The phrase itself is a [[phonetic palindrome]].
File:Ambigramme Merci - animation.gif|[[Point reflection]] ambigram [[:wikt:merci#English|''merci'']].
File:Ambigram Home Away - red and yellow - animation.gif|"Home / Away", 180° rotational hetero-ambigram.
File:Lift London red circle logo.svg|[[Lift London|"Lift"]], half-turn ambigram logo.
</gallery>
{{anchor|mirror ambigram}}
===Reflection===

A [[Mirror image|mirror]] or [[Reflection (physics)|reflection]] ambigram is a design that can be read when reflected in a [[mirror]] vertically, horizontally, or at 45 degrees,<ref name="AmbigramTypes" /> giving either the same word or another word or phrase.

====Vertical axis====

[[File:Ambigram I love you.png|thumb|Vertical axis reflection ambigram "Love you", with the letter I added over like in a totem ambigram.]]

[[File:Ambigram Perfect.png|thumb|left|"[[Perfection|Perfect]]", vertical axis mirror ambigram.]]

[[File:Ambigram Nothing written.jpg|thumb|"Nothing written", [[self-referential]] visual wordplay, vertical axis reflection.]]

[[File:Historical ambigram logo MAOAM 1900s.svg|thumb|left|Historical [[Maoam]] logo (candy), vertical axis mirror ambigram, between 1900 and 1931.]]

When the [[Reflection (physics)|reflecting]] surface is vertical (like a [[mirror]] for example), the calligraphic design is a ''vertical axis mirror ambigram''.

The "museum" ambigram is almost natural with mirror symmetry, because the first two letters are easily exchanged with the last two, and the lowercase letter e can be transformed into s by a fairly obvious typographical acrobatics.<ref name="PourLaScience">{{cite journal |language=fr |author1=Jean-Paul Delahaye|author1-link=Jean-Paul Delahaye |title=Ambigrammes |newspaper=[[Pour la Science]] |date=2004-09-01|url=https://www.pourlascience.fr/sd/logique/ambigrammes-1012.php |access-date=2021-10-06}}.</ref>

Vertical axis mirror ambigrams find clever applications in [[mirror writing]] (or [[specular writing]]), that is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the [[mirror image]] of normal writing: it appears normal when it is reflected in a [[mirror]]. For example, the word "ambulance" could be read frontward and backward in a vertical axis reflective ambigram. Following this idea, the French artist Patrice Hamel created a mirror ambigram saying "[[:wikt:entrée#Noun 2|entrée]]" (''entrance'', in French) one way, and "[[:wikt:sortie#Noun 2|sortie]]" (''exit'') the other way, displayed in the giant glass façade of the [[Gare du Nord]] in [[Paris]], so that the travelers coming in read ''entrance'', and those leaving read ''way out''.<ref name="PatriceHamelLeMonde">{{Cite web|title=Patrice Hamel, magicien des lettres|url=https://www.lemonde.fr/blog/lunettesrouges/2006/05/26/2006_05_patrice_hamel_m/|access-date=2021-08-07|website=Le Monde|date=26 May 2006|language=fr}}</ref>
{{clear}}

====Horizontal axis====

[[File:Ambigram Motel Water.png|thumb|"[[Motel]]" on the facade of a building is mirroring in the water of a [[pond]] to give "[[Water]]", [[self-referential]] concept using a [[Reflection (physics)|lake reflection]].]]

[[File:Ambigram_Body_Yoga,_mirror_symmetry.png|thumb|left|Horizontal axis mirror ambigram "[[Human body|Body]] / [[Yoga]]".]]

When the reflecting surface is horizontal (like a [[Reflection (physics)|mirroring lake]] for example), the calligraphic design is a ''horizontal axis mirror ambigram''.

The book ''Ambigrams Revealed'' features several creations of this type, like the word "Failure" mirroring in the water of a pond to give "Success", or "Love" changing into "Lust".<ref>{{harvsp|Prokhorov|2013|pp=131, 141}}.</ref>

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===Figure-ground===

[[File:Tessellation_ambigramme_Michel_Onfray_-_figure-fond.png|thumb|left|Figure-ground ambigram [[Michel Onfray]], revealing the surname in the [[negative space]] formed by the letters of the given name.]]

[[File:Ambigram tessellation Liar Jail - figure-ground.png|thumb|Figure-ground ambigram "Liar / Jail" (and incidentally also a [[tessellation]])]]

In a [[Figure–ground (perception)|figure / ground]] ambigram, letters fit together so the [[negative space]] around and between one word spells another word.<ref name="AmbigramTypes" />

In [[Gestalt psychology]], [[Figure–ground (perception)|figure–ground perception]] is known as identifying a ''figure'' from the back''ground''. For example, black words on a printed paper are seen as the "figure", and the white sheet as the "background".
In ambigrams, the [[Space (punctuation)|typographic space]] of the background is used as [[negative space]] to form new letters and new words. For example, inside a [[Letter case|capital]] [[H]], one can easily insert a lowercase [[i]].

The oil painting ''You & Me'' (US) by [[John Langdon (typographer)|John Langdon]] (1996) belongs to this category. The word "me" fills the space between the letters of "you".<ref name="USLangdon">{{cite web |title=US, painting |url=https://www.johnlangdon.net/works/us/ |website=[[John Langdon (typographer)|John Langdon]]|language=en |access-date=2021-08-28|archive-url= https://web.archive.org/web/20210227102053/https://www.johnlangdon.net/works/us/ |archive-date= 2021-02-27}}.</ref>

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===Tessellations===

[[File:Ambigram Future tessellation.png|thumb|Ambigram [[tessellation]] "[[Future]]", 180° [[rotational symmetry]]. Upside-down, the light-color letters "future" occupy the [[negative space]] between the dark color letters. Two tints, blue and black, separate each block.]]

With [[M. C. Escher|Escher]]-like [[tessellation]]s associated to word [[pattern]]s, ambigrams can be oriented in three, four, and up to six directions via rotational symmetries of 120°, 90° and 60° respectively,<ref name="AlainNicolasBnF">{{Cite book|title=Parcelles d'infini – promenade au jardin d'Escher |url=https://catalogue.bnf.fr/ark:/12148/cb40110766q|date=2018-04-06|access-date=2021-08-07|institution=[[Bibliothèque nationale de France]]|isbn=978-2-84245-075-5|language=fr|last1=Nicolas|first1=Alain|series=Belin, Pour la science }}</ref> such as those created by French artist Alain Nicolas.<ref name="AlainNicolasBooks">{{harvsp|Prokhorov|2013|p=33|loc=[https://books.google.com/books?id=dWTaRp2-HDUC&q=alain+nicolas+ambigrams+revealed&pg=PT53 "Alain Nicolas" in ''Ambigrams Revealed'']}}.</ref> Some words can also transform in the [[negative space]], but the multiplication of constraints often has the effect of reducing either the readability or the [[complexity]] of the [[calligraphy|designed]] words.

Ambigram tessellations are word [[puzzle]]s, in which [[geometry]] sets the rules.<ref name="AlainNicolasBooks" />

<gallery mode="packed" class="center">
File:Ambigram_Yeah_tessellation_-_animation.gif|[[Tessellation]] build with the natural ambigram "Yeah".
File:Tessellation_Serie_-_3_directions.png|3-directional ambigram "[[:wikt:série#Noun 2|Serie]]" (''series'', in French), [[tessellation]] using a 120° rotational symmetry. Created from a [[hexagon]].
</gallery>

{{Commons and category inline|links=[[commons:Category:Ambigram tessellations|Ambigram tessellations]]}}.

===Chain===

[[File:Chain_ambigram_Michel_Onfray.png|thumb|left|Chain ambigram [[Michel Onfray]].]]
[[File:Ambigramme Nouvel an - chaine.png|thumb|This chain ambigram "nouvel an" (''new year'', in French) reads upside down.]]

A chain ambigram is a design where a word (or sometimes words) are interlinked, forming a repeating chain.<ref name="AmbigramTypes" />
Letters are usually overlapped: a word will start partway through another word.
Sometimes chain ambigrams are presented in the form of a circle.
For example, the chain "...sunsunsunsun..." can flip upside down, but not the word "sun" alone, written horizontally.
A chain ambigram can be constituted of one to several elements. A single element ambigram chain is like a [[snake eating its own tail]]. A two-elements ambigram chain is like a snake eating the neighbor's tail with the neighbor eating the first snake's, and so on.

[[Scott Kim]]'s "''Infinity''" works, and that of [[John Langdon (typographer)|John Langdon]] "''Chain reaction''", are also [[self-referential]], since the first is infinite in the literal sense of the word, and the second, both reversible at 180° and interfering around the letter O, evokes a chain reaction.<ref>{{harvsp|Prokhorov|2013|p=37}}.</ref>

===Spinonyms===

A {{ill|spinonym|lt=''spinonym''|de|spinonym}} is a type of ambigram in which a word is written using the same [[glyph]] repeated in different [[Orientation (geometry)|orientations]].<ref name="Prokhorov2013" />
WEB is an example of a word that can easily be made into a spinonym.

<gallery class="center">
File:Motor Bike Expo logo.svg|{{ill|Motor Bike Expo|lt=''MBE''|it|Motor Bike Expo}} (Motor Bike Expo) spinonym logo. The same [[glyph]] is repeated in three different [[Orientation (geometry)|orientations]].
File:Spinonym neun.JPG|Spinonym "[[9 (number)|neun 9]]" (German for nine), five times the same [[glyph]] repeated in different [[Orientation (geometry)|orientations]].
File:Ambigram spinonym Happy New Year.png|"Happy new year" spinonym, the same [[glyph]] in different [[Orientation (geometry)|orientations]] shapes the twelve letters of the sentence.
</gallery>

===Perceptual shift===

[[File:Wave-particle.jpg|thumb|Perceptual shift ambigram, [[Wave-particle duality|''Wave'' and ''Particle'']], by [[Douglas Hofstadter]].]]

[[File:TheCat.svg|thumb|left|Ambiguous letter that can be interpreted as a H or as an A.]]

[[Perceptual]] [[Cognitive shift|shift]] ambigrams, also called "oscillation" ambigrams, are designs with no [[symmetry]] but can be read as [[Ambiguous image|two different words]] depending on how the curves of the letters are interpreted.<ref name="AmbigramTypes" /> These ambigrams work on the principle of [[Rabbit–duck illusion|rabbit-duck]]-style ambiguous images.

For example [[Douglas Hofstadter]] expresses the dual nature of light as revealed by physics with his perceptual shift ambigram [[Wave-particle duality|''Wave / Particle'']].

{{clear}}

===90° rotational===

[[File:Ambigram Wrong! Ignore (90 degrees rotational symmetry - animated).gif|thumb|left|"[[Apathy|Ignore]] [[Wrong]]!", also "Wrong! / Ignore", 90° rotational symmetry.]]

[[File:Ambigramm Jude Muslim (black and red - animated).gif|thumb|90° rotational ambigram "[[Jude, brother of Jesus|Jude]] / [[Muslim]]" (''[[:wikt:Jude#German|Jew]] / [[:wikt:Muslim#German|Muslim]]'' in German) (and incidentally also a chain ambigram).]]

"Quarter-turn" ambigrams or 90° [[rotational symmetry|rotational]] ambigrams turn [[clockwise]] or [[counterclockwise]] to express different meanings.<ref name="polster" /> For example, the letter U can turn into a C and reciprocally, or the letters M or W into an E.<ref name="Prokhorov2013" />

{{clear}}

===Totem===

[[File:Maria_monogram_in_Franciscan_church_Budapest.jpg|thumb|left|This historical ''Maria'' [[monogram]] is close to a totem ambigram, almost symmetrical over the vertical axis.]]

{{multiple image
 | width = 100
 | image1 = Alabama_A%26M_Bulldogs_logo.svg
 | caption1 = The [[Alabama A&M University]] has a totem mirror ambigram logo.
 | image2 = Ambigram Hot dog.png
 | caption2 = Words crossing or totem ambigram "[[Hot dog]]", vertical axis reflection symmetry.
}}

A totem ambigram is an ambigram whose letters are stacked like a [[Totem pole|totem]], most often offering a vertical axis [[Axial symmetry|mirror symmetry]].
This type helps when several letters fit together, but hardly the whole word.
For example, in the {{ill|Maria monogram|lt=''Maria'' monogram|hu|Mária-monogram}}, the letters M, A and I are individually symmetrical, and the pairing R/A is almost naturally mirroring.
When adequately stacked, the 5 letters produce a nice totem ambigram, whereas the whole name "Maria" would not offer the same cooperativeness.

The ambigrammist artist [[John Langdon (typographer)|John Langdon]] designed several totemic assemblages, such as the word "METRO" composed of the symmetrical letter M, then section ETR, and below O; or the sentence "THANK YOU", vertical assembly of T, H, A, then of the symmetric NK couple, then finally Y, O, U.<ref name="TotemLangdon">{{cite web |title=Ambigrams, Logos and word art – Category Totem |url=https://www.johnlangdon.net/projects/category/totem/ |website=[[John Langdon (typographer)|John Langdon]]|language=en |access-date=2021-08-28|archive-url= https://web.archive.org/web/20201024100016/https://www.johnlangdon.net/projects/category/totem/ |archive-date= 2020-10-24}}.</ref>

{{clear}}

===Fractal===

In mathematics, a [[fractal]] is a geometrical [[shape]] that exhibits [[Invariant (mathematics)|invariance]] under scaling.
A piece of the whole, if enlarged, has the same geometrical features as the entire object itself.
A fractal ambigram is a sort of space-filling ambigrams where the [[Tessellation|tiled]] word branches from itself and then shrinks in a [[self-similar]] manner, forming a [[fractal]].<ref name="Fractals">{{Cite web|title=Fractals, ambigrams, and more…|url=https://punyamishra.com/fractals-ambigrams-and-more/|access-date=2021-08-07|website=Punya Mishra's web|language=en}}</ref>
In general, only a few letters are constrained in a fractal ambigram. The other letters don't need to look like any other, and thus can be shaped freely.

===3-dimensional===

[[File:Godel escher bach abmigram.png|thumb|left|The 3D ambigram "GEB" (for ''[[Gödel, Escher, Bach]]'') on the cover of [[Douglas Hofstadter|Hofstadter]]'s book.]]

[[File:3d-ambigram.jpg|thumb|Three-dimensional ambigram, ''ABC''.]]

A [[3D modeling|3D]] ambigram is a design where an object is presented that will appear to read several letters or words when viewed from different angles.
Such designs can be generated using [[constructive solid geometry]], a technique used in [[solid modeling]], and then physically constructed with the [[rapid prototyping]] method.

3-dimensional ambigram [[sculptures]] can also be achieved in [[plastic arts]]. They are [[Volume rendering|volume]] ambigrams.

The original 1979 edition of [[Douglas Hofstadter|Hofstadter]]'s ''[[Gödel, Escher, Bach]]'' featured two 3-D ambigrams on the cover.<ref name="CoverGEB">{{Cite web|title=Godel, Escher, Bach: An Eternal Golden Braid|url=https://www.nationalbook.org/books/godel-escher-bach-an-eternal-golden-braid/|access-date=2021-08-07|website=[[National Book Foundation]]|language=en|archive-url= https://web.archive.org/web/20210728051538/https://www.nationalbook.org/books/godel-escher-bach-an-eternal-golden-braid/ |archive-date=2021-07-28}}</ref>

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===Complex===

Complex ambigrams are ambigrams involving more than one symmetry, or satisfying the criteria for several types. For example, a complex ambigram can be both rotational and mirror with a 4-fold [[Dihedral group|dihedral]] symmetry. Or a spinonym that reads upside down is also a complex ambigram.

<gallery mode="packed" class="center" heights="180">
File:Oxo_Bouillon_Liebig,_Reclams_Universum_1905.jpg|The logo [[Oxo (food)|Oxo]] has a 4-fold [[Dihedral group|dihedral]] symmetry (mirror and 180° rotational ambigram).
File:EDC logo.svg|The famous [[DJ]] [[Étienne de Crécy]] has a complex ambigram logo "EDC", mirroring through a horizontal axis, and figure-ground type with a [[power plug]] [[pictogram]] inserted in the [[negative space]].
File:Ambigram Dig hole Die.png|4-fold [[Dihedral group|dihedral]] symmetrical ambigram (mirror and rotational) "[[Burial|Dig hole]], [[Death|Die]]".
</gallery>

==Symbols==

===Languages===

[[File:Mirror writing2.jpg|thumb|left|Mirror ambigram depicting the phrase [[wikt:علي|علي]] [[wikt:ولي|ولي]] [[wikt:الله|الله]] (''[[Ali]] is the vicegerent of God'', in [[Arabic alphabet|Arabic]]), Ottoman panel, between 1720 and 1730.]]

{{multiple image
 | width = 160
 | image1 = 앰비그램 곰 문 (ambigram).png
 | caption1 = Ambigram [[wikt:곰|곰]] / [[wikt:문|문]] (''Bear / Door'', in Korean), 180° rotational symmetry.
 | image2 = Ambigram of বাংলা by MS Sakib.svg
 | caption2 = The word "[[wikt:বাংলা#Bengali|বাংলা]]" (''Bangla'' or Bengali, in Bengali), half-turn ambigram.
}}

Ambigrams exist in many languages. With the [[Latin alphabet]], they generally mix [[lowercase]] and [[uppercase]] letters. But words can also be symmetrical in other alphabets, like [[Arabic alphabet|Arabic]], [[Bengali alphabet|Bengali]], [[Cyrillic alphabets|Cyrillic]], [[Greek alphabet|Greek]], and even in [[Chinese characters]] and Japanese [[kanji]].

In [[Korean language|Korean]], [[wikt:곰|곰]] (bear) and [[wikt:문|문]] (door), [[wikt:공|공]] (ball) and [[wikt:운|운]] (luck), or [[wikt:물|물]] (water) and [[wikt:롬|롬]] ([[ROM]]) form a natural rotational ambigram. Some syllables like [[wikt:응|응]] (yes), [[wikt:표|표]] (ticket/signage) or [[wikt:를|를]] (''object particle''), and words like "허리피라우" (straighten your back) also make full ambigrams.

The [[han character]] meaning "hundred" is written [[wikt:百|百]], that makes a natural 90° rotational ambigram when the [[glyph]] makes a quarter turn counterclockwise, one sees "100".<ref name="ChineseAmbigrams">{{Cite book|title=Chinese-English Ambigrams|url=https://www.cogsci.indiana.edu/phard.html|last=Moser|first=David|language=en}}</ref>

{{Commons and category inline|links=[[commons:Category:Ambigrams by language|Ambigrams by language]]}}.

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===Numbers===

[[File:Ambigram-8-eight-math-2-1-5-rotation-mirror-basile-morin.gif|thumb|left|Mirror and rotational ambigram of an arithmetic operation illustrating the [[commutative property]] in [[addition]].<ref name="NazarethCollege">{{Cite web|url=https://www2.naz.edu/files/9215/0531/3121/v12n1.pdf|website=[[Nazareth College (New York)]]|title=Our Renowned Newsletter - The Renowned Brown|date=2017|first=Matt|last=Koetz|language=en|archive-url=https://web.archive.org/web/20221116043213/https://www2.naz.edu/files/9215/0531/3121/v12n1.pdf|archive-date=2022-11-16 |access-date=2022-11-10}}</ref>]]

{{multiple image
 | direction = vertical
 | image1 = Sochi_2014_(Emblem).svg
 | caption1 = Although not totally symmetrical, the [[2014 Winter Olympics|Sochi 2014 (Olympic games)]] official logo offers mirror and rotational symmetries, linking the numbers to the letters like an ambigram.
 | image2 = Ambigram_Rio_2016.png
 | caption2 = [[Rio 2016]] (Olympic games), half-turn rotational ambigram logo containing letters and [[Numerical digit|digits]].
}}

An ambigram of numbers, or ''numeral ambigram'', contains [[numerical digit]]s, like [[1]], [[2]], [[3]]...<ref name="Prokhorov2013" />

In [[mathematics]], a [[palindromic number]] (also known as a ''numeral palindrome'') is a number that remains the same when its digits are [[reflectional symmetry|reversed]] through a vertical axis (but not necessarily visually). The palindromic numbers containing only 1, 8, and 0, constitute natural numeric ambigrams (visually [[reflectional symmetry|symmetrical]] through a [[mirror]]). Also, because the [[glyph]] [[2]] is graphically the [[mirror image]] of [[5]], it means numbers like 205 or 85128 are natural numeral mirror ambigrams. Though not palindromic in the mathematical sense, they read frontward and backward like real ambigrams.

A [[strobogrammatic number]] is a number whose numeral is [[rotationally symmetric]], so that it appears the same when rotated 180 degrees. The numeral looks the same right-side up and upside down (e.g., 69, 96, 1001).<ref name="BritannicaStrobo">{{Cite web|title=Strobogrammatic number|url=https://www.britannica.com/science/strobogrammatic-number|access-date=2021-09-19|website=[[Encyclopædia Britannica]]|language=en}}</ref><ref name=Britannica>{{cite web|last1=Schaaf|first1=William L.|title=Number game|url=https://www.britannica.com/topic/number-game#ref396109|website=Encyclopedia Britannica|access-date=22 January 2017|date=1 March 2016|orig-date=1999}}</ref><ref name="TheWeekAmbigrams">{{Cite web|first=Judith B.|last=Herman|title=Palindromes, anagrams, and 9 other names for alphabetical antics|url=https://theweek.com/articles/464433/palindromes-anagrams-9-other-names-alphabetical-antics|access-date=2022-02-17|website=[[The Week]]|language=en|date=2015-01-09|archive-url=https://web.archive.org/web/20220217033819/https://theweek.com/articles/464433/palindromes-anagrams-9-other-names-alphabetical-antics|archive-date=2022-02-17}}</ref>

Some [[Calendar date|dates]] are natural numeral ambigrams.<ref name="TheWashingtonPostPalindromeDays">{{Cite news|author=Scott Duke Kominers|title=2021 Was a Mess, Unless You Count the Palindrome Days|url=https://www.washingtonpost.com/business/2021-was-a-mess-unlessyou-countthe-palindrome-days/2021/12/31/936d31a0-6a3e-11ec-9390-eae241f4c8b1_story.html|access-date=2022-02-23|newspaper=[[The Washington Post]]|language=en|date=2021-12-31|archive-url=https://web.archive.org/web/20220223024423/https://www.washingtonpost.com/business/2021-was-a-mess-unlessyou-countthe-palindrome-days/2021/12/31/936d31a0-6a3e-11ec-9390-eae241f4c8b1_story.html|archive-date=2022-02-23}}</ref>
In March 1961, artist [[Norman Mingo]] created an upside-down cover for ''[[Mad magazine]]'' featuring an ambigram of the current year. The title says "No matter how you look at it... it's gonna be a ''Mad'' year. 1961, the first upside-down year since 1881."<ref name="Mad1961">{{Cite web|title=Mad 61 March 1961|url=https://www.madcoversite.com/mad061.html|access-date=2021-08-15|website=Mad Cover Site|archive-url=https://web.archive.org/web/20201107124605/https://www.madcoversite.com/mad061.html|archive-date=2020-11-07|language=en}}</ref>
Tuesday, 22 February 2022, was a palindrome and ambigram date called "[[Twosday]]" because it contained reversible 2 (two).<ref name="CNNTwosday">{{Cite web|first=Megan|last=Marples|title=Happy Twosday! Don't miss out celebrating the coolest date of the decade|url=https://edition.cnn.com/2022/02/22/world/twosday-february-22-wellness/index.html|access-date=2022-02-17|website=[[CNN]]|language=en|date=2022-02-22|archive-url=https://web.archive.org/web/20220222121157/https://edition.cnn.com/2022/02/22/world/twosday-february-22-wellness/index.html|archive-date=2022-02-22}}</ref><ref name="TheGuardianTwosday">{{Cite web|first=Rachel|last=Hall|title=22.02.2022: social media gets excited over palindrome 'Twosday'|url=https://www.theguardian.com/uk-news/2022/feb/22/22022022-social-media-gets-excited-over-palindrome-twosday|access-date=2022-02-23|website=[[The Guardian]]|language=en|date=2022-02-22|archive-url=https://web.archive.org/web/20220222164234/https://www.theguardian.com/uk-news/2022/feb/22/22022022-social-media-gets-excited-over-palindrome-twosday|archive-date=2022-02-22}}</ref><ref name="USATodayTwosday">{{Cite web|first=Charles |last=Curtis |title=Happy Twosday! Everyone's celebrating the fact that it's 2/22/22 with memes|url=https://ftw.usatoday.com/lists/twosday-2-22-22-memes-what-is-it-palindrome-ambigram|access-date=2022-02-23|website=[[USA Today]]|language=en|date=2022-02-22|archive-url=https://web.archive.org/web/20220222124445/https://ftw.usatoday.com/lists/twosday-2-22-22-memes-what-is-it-palindrome-ambigram|archive-date=2022-02-22}}</ref>

Ambigrams of numbers receive most attention in the realm of [[recreational mathematics]].<ref name="polster" /><ref name="RecreaMathsNYT">{{Cite news|title=The Importance of Recreational Math|url=https://www.nytimes.com/2015/10/12/opinion/the-importance-of-recreational-math.html|access-date=2021-08-07|website=The New York Times|date=12 October 2015|language=en|last1=Suri|first1=Manil}}</ref>

Ambigrams with numbers sometimes combine letters and numerical digits. Because the number 5 is approximately shaped like the letter S, the number 6 like a lowercase b, the number 9 like the letter g, it is possible to play on these similarities to design ambigrams. A good example is the [[2014 Winter Olympics|Sochi 2014 (Olympic games)]] logo where the four [[glyph]]s contained in 2014 are exact symmetries of the four letters S, o, i and h, individually.<ref name="Sochi">{{Cite web|title=SOCHI 2014 The brand|url=https://olympics.com/en/olympic-games/sochi-2014/logo-design|access-date=2021-08-07|website=Olympics.com|date=4 January 2021|language=en}}</ref>

===Others===
[[File:Berg lulu palindrome mirror point.png|thumb|Palindrome with [[musical note]]s, here the centre part of [[Alban Berg]]'s opera ''[[Lulu (opera)|Lulu]]'']]

As [[alphabet letters]] are [[glyph]]s used in the [[writing system]]s to express the [[language]]s visually, other [[symbol]]s are also used in the world to code other fields, like the [[Prosigns for Morse code|prosigns]] in the [[Morse code]] or the [[musical notes]] in [[music]].

Similarly to the ambigrams of letters, the ambigrams with other symbols are generally visually symmetrical, either [[point reflection|point reflective]] or [[axial symmetry|reflective through an axis]].

The international [[Morse code]] [[distress signal]]  [[SOS]] {{morse|dot|dot|dot|dash|dash|dash|dot|dot|dot}} is a natural ambigram constituted of dots and dashes. It flips upside down or through a mirror.

In morse code, the letter P coded {{morse|dot|dash|dash|dot}} and the letter R coded {{morse|dot|dash|dot}} are individually symmetrical, like many other letters and numbers. Also, the letter G coded {{morse|dash|dash|dot}} is the exact reverse of the letter W coded {{morse|dot|dash|dash}}. Thus, the combination {{morse|dash|dash|dot}} / {{morse|dot|dash|dash}} coding the pairing G/W constitutes a natural ambigram. Consequently, meaningful natural ambigrams written in morse code certainly exist, like for example the words "gnaw" {{morse|dash|dash|dot}}{{morse|dash|dot}} {{morse|dot|dash}}{{morse|dot|dash|dash}}, "[[Dou (surname)|Dou]]" {{morse|dash|dot|dot}} {{morse|dash|dash|dash}} {{morse|dot|dot|dash}} or "[[mom]]" {{morse|dash|dash}} {{morse|dash|dash|dash}} {{morse|dash|dash}}.<ref name="SunJournalWow" /><ref name="JohnCookMorseCodePalindromes">{{Cite web|title=Morse code palindromes|url=https://www.johndcook.com/blog/2021/09/04/morse-code-palindromes/|access-date=2021-08-07|website=JohndCook|language=en|archive-url=https://web.archive.org/web/20210906131351/https://www.johndcook.com/blog/2021/09/04/morse-code-palindromes/|archive-date=2021-09-06}}</ref><ref name="ScrussMorsePalindromes">{{Cite web|title=Morse Palindromes|url=https://scruss.com/blog/2013/10/12/morse-palindromes-or-cq-christian-bok/|access-date=2021-08-07|website=Scruss|date=12 October 2013|language=en|archive-url= https://web.archive.org/web/20200804045053/http://scruss.com/blog/2013/10/12/morse-palindromes-or-cq-christian-bok/ |archive-date=2020-08-04}}</ref>

In [[music]], the interlude from [[Alban Berg]]'s opera ''[[Lulu (opera)|Lulu]]'' is a [[palindrome]], thus the [[Sheet music|score]] made up of [[musical note]]s is almost symmetrical through a vertical axis.<ref name="Lulu">{{Cite web|title=Lulu|url=https://www.bl.uk/works/lulu|access-date=2021-08-07|website=[[British Library]]|language=en|archive-date=2021-09-25|archive-url=https://web.archive.org/web/20210925030200/https://www.bl.uk/works/lulu|url-status=dead}}</ref>

In [[biology]], researchers study the ambigrammatic property of [[narnavirus]]es by using visual representations of the symmetrical sequences.<ref name="Nature" /><ref name="QuantaMagazine" /><ref name="BioRxiv">{{cite journal |doi= 10.1093/ve/veab038| biorxiv=10.1101/2021.02.16.431493 | title=Polymorphism of genetic ambigrams | year=2021 | last1=Dudas | first1=Gytis | last2=Huber | first2=Greg | last3=Wilkinson | first3=Michael | last4=Yllanes | first4=David | journal=Virus Evolution | volume=7 | issue=1 | pages=veab038 | pmid=34055388 | pmc=8155312 }}</ref>

==Fields==

===Art===

====Calligraphy and typography====

[[File:Typism book one ambigram Love Song by Basile Morin.jpg|thumb|left|Ambigram ''[[Love song|Love Song]]'' published in a [[typography]] book (''Typism'').]]

{{multiple image
 | width = 180
 | image1 = Ambigram_Soul_of_Laos.png
 | caption1 = [[Calligraphic]] color-reversal ambigram ''[[Soul]] of [[Laos]]'',  published in the book ''Ambigrams Revealed''.<ref>{{harvsp|Prokhorov|2013|p=122}}.</ref>
 | image2 = Ambigramm Danke (pink).png
 | caption2 = [[Calligraphic]] design [[:wikt:Danke#German|Danke]] (''thanks'', in German) and half-turn ambigram.
}}

Instead of simply writing them, ambigram [[lettering]] covers the [[art]] of [[drawing]] [[alphabet letters|letters]]. In ambigram calligraphy, each letter acts as an [[illustration]], each letter is created with attention to detail and has a unique role within a [[Composition (visual arts)|composition]]. Lettering ambigrams do not translate into combinations of alphabet letters that can be used like a [[typeface]], since they are created with a specific candidate in mind.

The [[calligrapher]], [[graffiti]] writer and [[graphic designer]] [[Niels Shoe Meulman]] created several rotational ambigrams like the number "fifty",<ref>{{harvsp|Prokhorov|2013|p=139}}.</ref> the names "Shoe / Patta",<ref>{{harvsp|Prokhorov|2013|p=146}}.</ref> and the opposition "Love / Fear".<ref name="MeulmanLoveFear">{{Cite web|title=Fear less Love More (intense) / Niels Shoe Meulman|url=https://www.unrulygallery.com/product/fear-less-love-more-intense-niels-shoe-meulman|access-date=2021-08-07|website=Unruly Gallery|language=en}}</ref>

The [[book cover|cover]] of the 7th volume of the [[typography]] book ''Typism'' is an ambigram drawn by [[Nikita Prokhorov (graphic artist)|Nikita Prokhorov]].<ref name="Typism7">{{Cite web|title=Sneak peek at Book Logo 7|url=https://www.typismcommunity.com/blog/sneak-peek-at-logo-7|access-date=2021-08-07|website=Typism Community|language=en}}</ref>

The  American [[typeface|type]] [[typography|designer]] [[Mark Simonson]] designed poetic and [[humorous]] ambigrams, such as the words "Revelation", "Typophile", and the symbiosis "Drink / Drunk".<ref>{{harvsp|Prokhorov|2013|p=145}}.</ref> The last one makes a [[visual pun]] when printed on a [[shot glass]], sold commercially.<ref name="DrinkDrunk">{{Cite web|title=Drink / Drunk Ambigram Shot Glasses|url=https://odditymall.com/drink-drunk-ambigram-shot-glasses|access-date=2021-08-07|website=Oddity Mall|date=10 March 2015|language=en}}</ref>

{{clear}}

====Logos====

{{multiple image
 | direction = vertical
 | align = left
 | image1 = Ambigram_New_Man_logo_metal_button_on_a_shirt_animated_gif.gif
 | caption1 = The rotational logo ''New Man'' created by [[Raymond Loewy]] in 1968 is a natural ambigram.
 | image2 = Ambigram_logo_Handy_-_company.png
 | caption2 = The online [[two-sided market]]place for residential cleaning [[Handy (company)|Handy]] has a 180° rotational ambigram logo.
}}

{{multiple image
 | direction = vertical
 | image1 = SUN microsystems logo ambigram.png
 | caption1 = [[Sun Microsystems|Sun]] (Microsystems) logo designed by [[Vaughan Pratt]] in 1982, chain ambigram, spinonym, 90° and 180° rotational symmetries.
 | image2 = 縦型_どん兵衛_(36386429205).jpg
 | caption2 = [[Nissin Foods|Nissin]] (Foods) ambigram visual identity (half-turn).
}}

[[File:VOA logo (lighter blue).svg|thumb|Logo of [[Voice of America]].]]

Since they are visually striking, and sometimes surprising, ambigram words find large application in [[logo|corporate logos]] and [[wordmark]]s, setting the visual [[Corporate identity|identity]] of many organizations, trademarks and brands.<ref name="Langdon2005">{{harvsp|Langdon|2005}}.</ref>

In 1968<ref name="NewManLogobook">{{Cite web|title=New Man|url=http://www.logobook.com/logo/new-man/|access-date=2021-08-10|website=Logobook|language=en}}</ref> or 1969, [[Raymond Loewy]] designed the rotational {{ill|New Man (clothing)|lt=''New Man''|fr|New Man}} ambigram logo.<ref>{{cite web|url=http://raymond-loewy.un-jour.org/biographie_raymond_loewy.html|title=Raymond Loewy Biographie|website=Raymond-loewy.un-jour.org|language=fr|access-date=6 November 2016|archive-url=https://web.archive.org/web/20090608042138/http://raymond-loewy.un-jour.org/biographie_raymond_loewy.html|archive-date=8 June 2009}}</ref><ref name="Wired">{{cite journal|url=https://www.wired.com/culture/art/multimedia/2009/04/pl_arts?slide=6&slideView=3|title=Typography Two Ways: Calligraphy With a Twist|last=Pierce|first=Scott|date=20 May 2009|journal=[[Wired (website)|Wired]]|access-date=6 November 2016}}</ref><ref name="NewManLJDN">{{cite web |title=New Man, à l'envers, à l'endroit |url=https://www.journaldunet.com/ebusiness/crm-marketing/1082684-ces-logos-qui-ont-un-secret/1082690-new-man |website=Le Journal du Net|date=16 December 2013 |language=fr |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210923090740/https://www.journaldunet.com/ebusiness/crm-marketing/1082684-ces-logos-qui-ont-un-secret/1082690-new-man |archive-date= 2021-09-23}}.</ref>

The mirror ambigram [[DeLorean Motor Company]] logo, designed by Phil Gibbon, was first used in 1975.<ref name="LogosMarcasDMC">{{cite web |title=DMC LOGO |url=https://logos-marcas.com/dmc-logo/ |website=LogosMarcas |language=es |access-date=2021-08-28|archive-url=https://web.archive.org/web/20211006033130/https://logos-marcas.com/dmc-logo/|archive-date=2021-10-06}}</ref><ref>{{Cite magazine|date=July 1977|title=1975 Prototype Logo|url=http://www.entermyworld.com/cat/articles/caranddriver/cdjul771x1.jpg|magazine=[[Car and Driver]]|access-date=6 November 2016}} In 1977, only the single 1975 prototype existed. There are multiple visible differences between the prototype vehicle and later production models, including the design of the front end.</ref><ref>{{Cite magazine|date=1 November 1977|title=Motor City eyebrows were raised when DeLorean married model Cristina Ferrare.|url=http://www.entermyworld.com/cat/articles/us/usnov177c1x1.jpg|magazine=[[US Magazine]]|access-date=6 November 2016}}</ref>

Robert Petrick designed the invertible ''[[Angel (American band)|Angel]]'' logo<ref>{{harvsp|Prokhorov|2013|p=133}}.</ref> in 1976.

The logo [[Sun Microsystems|Sun]] (Microsystems) designed by professor [[Vaughan Pratt]]<ref name="SunLogobook">{{Cite web|title=Designers: Vaughan Pratt|url=http://www.logobook.com/designer/vaughan-pratt/|archive-url=https://web.archive.org/web/20200809144516/http://www.logobook.com/designer/vaughan-pratt/|archive-date=2020-08-09|access-date=2021-08-07|website=Logobook|language=en}}</ref> in 1982 fulfills the criteria of several types: chain ambigram, spinonym, 90° and 180° rotational symmetries.

The Swedish pop group [[ABBA]] owns a mirror ambigram logo stylized '''AᗺBA''' with a reversed B, designed by {{ill|Rune Söderqvist|lt=Rune Söderqvist|sv|Rune Söderqvist}}<ref name="SverigesRadioABBA">{{Cite news|title=Creator of Abba logo dies|url=https://sverigesradio.se/artikel/5952951|access-date=2021-09-20|website=[[Sveriges Radio]]|date=September 2014|language=en}}</ref> in 1976.<ref name="AbbaSite">{{Cite web|title=Rune Söderqvist|url=https://abbasite.com/people/rune-soderqvist/|access-date=2021-08-07|website=[[ABBA]]|date=13 April 2018|language=en}}</ref>

The [[Ventura, California|Ventura]] logo of the Visitors & Convention Bureau's board, in California, cost {{Currency|25000|USD}} and was created in 2014 by the DuPuis group. It uses a 180° rotational symmetry.<ref name="VCStarVenturaLogo">{{cite web |title=Marketing Ventura: City moves to refine its image with new brand and logo |url=https://archive.vcstar.com/business/marketing-ventura-city-moves-to-refine-its-image-with-new-brand-and-logo-ep-292089246-351497721.html/ |website=[[Ventura County Star]]|language=en |access-date=2021-09-27|archive-url= https://web.archive.org/web/20171225091657/http://archive.vcstar.com/business/marketing-ventura-city-moves-to-refine-its-image-with-new-brand-and-logo-ep-292089246-351497721.html |archive-date= 2017-12-25}}</ref><ref name="VisitVentura">{{cite web |title=Home page|url=https://visitventuraca.com/ |website=VisitVenturaCa.com |language=en |access-date=2021-09-27|archive-url= https://web.archive.org/web/20191201105509/https://visitventuraca.com/ |archive-date= 2019-12-01}}</ref>

Other famous ambigram logos include: <!-- by alphabetical order -->
the insurance company [[Aviva]];<ref name="GlassdoorAviva">{{Cite web|title=Aviva Canada|url=https://www.glassdoor.com/Interview/Aviva-Canada-Interview-Questions-E137164.htm|access-date=2021-08-07|website=[[Glassdoor]]|language=en|archive-url=https://web.archive.org/web/20140102020920/http://www.glassdoor.com/Interview/Aviva-Canada-Interview-Questions-E137164.htm |archive-date=2014-01-02}}</ref>
the [[acronym]] [[Capital Regional District|CRD]] (Capital Regional District) in the Canadian province of British Columbia;<ref name="CRDAmbigramLogo">{{Cite web|title=Summer Newsletter 2016 |url=https://www.crd.bc.ca/docs/default-source/parks-pdf/vip-summer-newsletter-2016.pdf |access-date=2021-08-07|website=[[Capital Regional District]]|language=en|archive-url= https://web.archive.org/web/20210921235735/https://www.crd.bc.ca/docs/default-source/parks-pdf/vip-summer-newsletter-2016.pdf |archive-date=2021-09-21}}</ref>
the American multinational corporation [[DXC Technology|DXC]] Technology;
the two-sided marketplace for residential cleaning [[Handy (company)|Handy]];<ref name="HandyLogo">{{cite web |title=Logo |url=https://styleguide.handy.com/brand-guidelines/logo |website=[[Handy (company)|Handy]] |language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210921234238/https://github.com/Handybook/handyguide/blob/master/brand-guidelines/logo.md |archive-date= 2021-09-21}}.</ref><ref name="BizJournalsHandy">{{cite web |title=Handybook Rebrands as Handy |url=https://www.bizjournals.com/boston/inno/stories/news/2014/09/16/handybook-rebrands-as-handy-starts-acting-like-the.html |website=[[Biz Journals]] |language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210921234757/https://www.bizjournals.com/boston/inno/stories/news/2014/09/16/handybook-rebrands-as-handy-starts-acting-like-the.html |archive-date= 2021-09-21}}.</ref>
the brand name of French premium high-speed train services [[InOui]];<ref name="LiberationInoui">{{cite web |title=Paris-Marseille, voyage au bout de l'appli |url=https://www.liberation.fr/debats/2019/06/21/paris-marseille-voyage-au-bout-de-l-appli_1735345/ |website=[[Libération]] |language=fr |date=2019-06-21|access-date=2021-09-20}}.</ref>
the French company specializing in ticketing and passenger information systems [[RATP Smart Systems|IXXI]];
the century-old brand [[Maoam]] of the confectionery manufacturer Haribo;<ref name="HariboMAOAM">{{Cite web|title=MAOAM|url=https://www.haribo.com/en-gb/products/maoam|access-date=2022-02-17|website=[[Haribo]]|language=en|archive-url=https://web.archive.org/web/20200925173044/https://www.haribo.com/en-gb/products/maoam|archive-date=2020-09-25}}</ref>
the American industrial rock band [[NIͶ]];
the Japanese food company [[Nissin Foods|Nissin]];
the biotechnology company [[Noxxon]] Pharma, founded in 1997;
the online travel agency [[Opodo]] in 2001;<ref name="OpodoJDN">{{cite web |title=Interview Nicolás de Santis, Directeur marketing Opodo |url=http://www.journaldunet.com/itws/it_desantis.shtml |website=Le Journal du Net |language=fr |access-date=2021-09-20|archive-url= https://web.archive.org/web/20200302012008/http://www.journaldunet.com/itws/it_desantis.shtml |archive-date= 2020-03-02}}.</ref>
the brand of food products [[Oxo (food)|OXO]]<ref name="NewYorkTimesOxo">{{Cite web|first=Rachel|last=Fabi|title=Sudden Inspirations|url=https://www.nytimes.com/2021/12/30/crosswords/daily-puzzle-2021-12-31.html|access-date=2022-02-23|website=[[The New York Times]]|language=en|date=2021-12-30|archive-url=https://web.archive.org/web/20220101033408/https://www.nytimes.com/2021/12/30/crosswords/daily-puzzle-2021-12-31.html|archive-date=2022-01-01}}</ref> born in 1899;
the video game [[POD (video game)|Pod]];
the American developer and manufacturer of audio products [[Sonos]];<ref name="TheVergeSonos">{{Cite web|title=New Sonos logo design pulses like a speaker when scrolled|url=https://www.theverge.com/2015/1/23/7876777/sonos-sound-wave-logo |access-date=2021-08-07|website=[[The Verge]]|date=23 January 2015 |language=en|archive-url= https://web.archive.org/web/20210907141058/https://www.theverge.com/2015/1/23/7876777/sonos-sound-wave-logo |archive-date=2021-09-07}}</ref>
the American professional basketball team Phoenix [[Phoenix Suns|Suns]];<ref name="NBASunsLogo">{{cite web |title=New Logos, Same Memories |date=2013-06-26 |url=https://www.nba.com/suns/new-logos-same-memories |website=[[NBA]] |language=en |access-date=2021-09-27|archive-url= https://web.archive.org/web/20160128082043/http://www.nba.com/suns/new-logos-same-memories |archive-date= 2016-01-28}}.</ref><ref name="NBASunsPhoenix">{{cite web |title=Phoenix Suns Unveil New Logos |date=2013-06-26 |url=https://www.nba.com/suns/phoenix-suns-unveil-new-logos |website=[[NBA]] |language=en |access-date=2021-09-27|archive-url= https://web.archive.org/web/20210627225158/https://www.nba.com/suns/phoenix-suns-unveil-new-logos |archive-date= 2021-06-27}}.</ref>
the German manufacturer of adhesive products [[UHU]];
the quadruple symmetrical logo [[Under Armour|UA]] from the American clothing brand '' Under Armour '';
the Canadian corporation mandated to operate intercity passenger rail service [[Via Rail|VIA]] in 1978;<ref name="LogobookVIA">{{cite web |title=Via Rail Canada |url=http://www.logobook.com/logo/via-rail-canada/ |website=Logobook |language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210120010802/http://www.logobook.com/logo/via-rail-canada/ |archive-date= 2021-01-20}}.</ref>
the American international broadcaster [[VOA]], born in 1942;
and the Malaysian mobile virtual network operator [[XOX]]. The student edition of the [[Tesco Clubcard]] used 180° rotational symmetry.<ref>{{Cite web|url=http://beerbubbles.com/|title=Simon Beer: Graphic Designer|website=beerbubbles.com}}</ref>

====Visual communication====

[[File:Biden-USA-Harris ambigram animated.gif|thumb|Ambigram "[[Joe Biden|Biden]] USA [[Kamala Harris|Harris]]" by [[Douglas Hofstadter]] conveying a political message during the [[2020 United States presidential election]].]]

[[File:Anna_(2019)_Logo.svg|thumb|The movie ''[[Anna (2019 feature film)|Anna]]'' by [[Luc Besson]] (2019) reveals on its [[Cinema poster|poster]] a mirror ambigram with a vertical axis.]]

Because they are [[visual pun]]s,<ref name="polster" /> ambigrams generally attract attention, and thus can be used in [[visual communication]] to broadcast a [[marketing]] or [[political]] message.

In France, a mirror ambigram "[[Penelope Gate|Penelope]] / [[:wikt:bénévole#French|benevole]]" legible through a horizontal axis became a [[meme]] on the web after its diffusion on [[Wikimedia Commons]].<ref name="PenelopeLeMatin">{{Cite news|title=Penelopegate le reflet qui fait rigoler|url=http://www.lematin.ch/culture/Penelopegate-le-reflet-qui-fait-rigoler/story/19106243|access-date=2021-08-15|archive-url=https://web.archive.org/web/20210805100208if_/https://www.lematin.ch/story/penelopegate-le-reflet-qui-fait-rigoler-691399631579|archive-date=2021-08-05|website=[[Le Matin (Switzerland)]]|date=6 February 2017|language=fr}}</ref>
[[Penelope Fillon]], wife of French politician and former Prime Minister of France [[François Fillon#Conviction for fraud|François Fillon]], is suspected of having received wages for a fictitious job. Ironically, her name through the mirror becomes [[:wikt:bénévole|benevole]] (''[[Voluntary action|voluntary]]'' in French), suggesting dedication for a free service. Shared tens of thousands of times on the [[social networks]], this [[humorous]] ambigram made the [[Marketing buzz#Positive vs. negative buzz|buzz]] via several French,<ref name="PenelopeTelestar">{{Cite web|title=Penelope Gate: la photo qui fait le buzz sur les réseaux sociaux depuis ce weekend|url=http://www.telestar.fr/article/penelope-gate-la-photo-qui-fait-le-buzz-sur-les-reseaux-sociaux-depuis-ce-weekend-photos-264816|access-date=2021-08-07|website=Telestar|date=6 February 2017|language=fr}}</ref> Belgian<ref name="PenelopeLeSoir">{{Cite web|title=Avec un miroir, Penelope devient «benevole|url=https://www.lesoir.be/art/1434265/article/soirmag/actu-soirmag/2017-02-06/avec-un-miroir-penelope-devient-benevole|date=2017-02-06|archive-url=https://web.archive.org/web/20170531142754/http://www.lesoir.be/1434265/article/soirmag/actu-soirmag/2017-02-06/avec-un-miroir-penelope-devient-benevole|archive-date=2017-05-31|access-date=2021-08-07|website=[[Le Soir]]|language=fr}}</ref><ref name="PenelopeSudinfo">{{Cite web|title=PenelopeGate: voici la photo qui fait le buzz sur les réseaux sociaux|url=http://www.sudinfo.be/1782364/article/2017-02-06/penelopegate-voici-la-photo-qui-fait-le-buzz-sur-les-reseaux-sociaux-depuis-ce-w|date=2017-02-06|archive-url=https://web.archive.org/web/20170714035324/http://www.sudinfo.be/1782364/article/2017-02-06/penelopegate-voici-la-photo-qui-fait-le-buzz-sur-les-reseaux-sociaux-depuis-ce-w|archive-date=2017-07-14|access-date=2021-08-15|website=Sudinfo|language=fr}}</ref> and Swiss<ref name="PenelopeLeMatin" /> [[News media|medias]].

Ambigrams are regularly used by [[advertising agency|communication agencies]] such as [[Publicis]] to engage the reader or the consumer through two-way messages.<ref name="happinessCampaignCBC">{{cite web|title=Ad Campaign Finds A Surprising Way To Talk About Depression|url=https://www.cbc.ca/strombo/news/clever-ad-campaign-highlights-signs-of-depression.html|access-date=2021-08-07|website=[[Canadian Broadcasting Corporation]]|language=en|date=2013-06-25|archive-url=https://web.archive.org/web/20210923001629/https://www.cbc.ca/strombo/news/clever-ad-campaign-highlights-signs-of-depression.html|archive-date=2021-09-23}}</ref>
Thus, in 2021, male first names transformed into female first names are included in a Swiss [[advertising campaign]] aimed at raising awareness about [[gender equality]]. An intriguing [[catchphrase]] typography upside down invites the reader to rotate the magazine, in which the first names "Michael" or "Peter" are transformed into "Nathalie" or "Alice".<ref name="ServiceplanHorizont">{{cite web|title=Serviceplan Suisse stellt die Gleichberechtigung auf den Kopf| url=https://www.horizont.net/schweiz/nachrichten/schweizer-kader-organisation-sko-serviceplan-suisse-stellt-die-gleichberechtigung-auf-den-kopf-192846|access-date=2021-08-07|website=Horizont (magazine)|language=de|date=2021-07-08|archive-url=https://web.archive.org/web/20210923024646/https://www.horizont.net/schweiz/nachrichten/schweizer-kader-organisation-sko-serviceplan-suisse-stellt-die-gleichberechtigung-auf-den-kopf-192846|archive-date=2021-09-23}}</ref><ref name="ServiceplanWerbewoche">{{cite web |title=Serviceplan Suisse turns ads upside down for SKO Swiss Leaders |url=https://www.werbewoche.ch/en/werbung/kampagnen/2021-07-08/serviceplan-suisse-stellt-fuer-sko-swiss-leaders-anzeigen-auf-den-kopf/ |website=Werbewoche |date=8 July 2021 |language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210923072707/https://www.werbewoche.ch/en/werbung/kampagnen/2021-07-08/serviceplan-suisse-stellt-fuer-sko-swiss-leaders-anzeigen-auf-den-kopf/ |archive-date= 2021-09-23}}.</ref>

In 2015 iSmart's logo on one of its travel [[battery charger|charger]]s went [[Viral phenomenon|viral]] because the brand's name turned out to be a natural ambigram that read "+[[Jew]]s!" upside down. The company noted that "...we learned a powerful lesson of what not to do when creating a [[logo]]."<ref name="iSmart/Jews!">{{cite web|url=https://www.vice.com/en/article/ismart-the-charger-that-says-jews/|title=This Charger that Says 'Jews' Is Today's Tech Fail|last=Hoffman|first=Jenn|date=9 May 2015|website=motherboard.com|publisher=[[Vice (magazine)|Vice]]|access-date=6 November 2016}}</ref>

[[Cinema poster]]s sometimes seduce observers with ambigram titles, such as that of [[Tenet (film)|Tenet]] by [[Christopher Nolan]], by central symmetry.<ref name="TenetVox" />
or [[Anna (2019 feature film)|Anna]] by [[Luc Besson]] around a vertical axis,<ref name="LaDepecheAnna">{{cite web |title="Anna": le dernier Luc Besson dévoile une bande-annonce musclée |date=2019-06-17 | url=https://www.ladepeche.fr/2019/06/17/anna-le-dernier-luc-besson-devoile-une-bande-annonce-musclee,8261328.php |website=[[La Dépêche du Midi]] |language=fr |access-date=2021-09-20|archive-url= https://web.archive.org/web/20190701174651/https://www.ladepeche.fr/2019/06/17/anna-le-dernier-luc-besson-devoile-une-bande-annonce-musclee,8261328.php |archive-date= 2019-07-01}}.</ref><ref name="LObsAnna">{{cite web |title="Anna" |date=2019-07-10 |url=https://www.nouvelobs.com/cinema/20190710.OBS15708/anna-vita-amp-virginia-les-films-a-voir-ou-pas-cette-semaine.html |website=[[L'Obs]] |language=fr |access-date=2021-09-20|archive-url= https://web.archive.org/web/20200801095036/https://www.nouvelobs.com/cinema/20190710.OBS15708/anna-vita-amp-virginia-les-films-a-voir-ou-pas-cette-semaine.html |archive-date= 2020-08-01}}.</ref>

<gallery mode="packed" class="center">
File:Penelope_benevole_ambigramme_de_Basile_Morin.jpg|Ambigram [[meme]] "[[Penelope Gate|Penelope]] / [[:wikt:bénévole#French|benevole]]" with a political message.
File:Ambigram_station_toilets_-_animated.gif|Half-turn [[traffic sign]] using a directional arrow [[symbol]] to display alternatively "[[Train station|Station]] / [[Toilets]]".
File:Ambigram_Avoid_the_plane.gif|[[Visual pun]] "Avoid the plane" to attract attention towards the [[environmental impact of aviation]].
File:IdaplatzAmbigram.jpg|A practical application of [[mirror writing|mirror]] ambigrams in a [[banner]] reading "Idaplatz fest" front and back ([[Zürich]], 2008).
</gallery>

====Comics====

[[File:Ambigrams by Gustave Verbeek (1904) - comics The Upside Downs of Little Lady Lovekins and Old Man Muffaroo - At the house of the writing pig.jpg|thumb|upright|Ambigrams in [[comics]] by [[Gustave Verbeek]] in 1904.]]

{{multiple image
 | direction = vertical
 | align = left
 | image1 = Ambigrams by Gustave Verbeek (1904) - comics The Upside Downs of Little Lady Lovekins and Old Man Muffaroo - The wonderful cure of the waterfall (panel 4).jpg
 | caption1 = Ambigrams in [[comics]] ''The Upside Downs of Little Lady Lovekins and Old Man Muffaroo'' by [[Gustave Verbeek]] containing ambigram [[Sentence (linguistics)|sentences]] in 1904.
 | image2 = Ambigrams by Gustave Verbeek (1904) - comics The Upside Downs of Little Lady Lovekins and Old Man Muffaroo - At the house of the writing pig (panel 4).jpg
 | caption2 = Another frame.
}}

The American artist and writer [[Peter Newell]] published a [[Point reflection|rotational]] ambigram in 1893 saying "Puzzle / The end" in the book containing [[reversible figure|reversible illustrations]] ''Topsys & Turvys''.<ref name="Topsys" />

In March 1904 the Dutch-American [[comic]] artist [[Gustave Verbeek]] used ambigrams in three consecutive strips of ''The UpsideDowns of old man Muffaroo and little lady Lovekins''.<ref name="Sunday Press"/> His comics were [[ambiguous image]]s, made in such a way that one could read the six-panel comic, flip the book and keep reading. In ''The Wonderful Cure of the Waterfall'' (13 March 1904) an Indian medicine man says 'Big waters would make her very sound', while when flipped the medicine man turns into an Indian woman who says  'punos dery, ery apew poom, serlem big'. Which is explained as, 'poor deary' several foreign words that meant that she would call the 'Serlem Big'. The next comic called ''At the House of the Writing Pig'' (20 March 1904), where two ambigram word [[Speech balloon|balloons]] are featured. The first features an angry pig trying to make the main protagonist leave by showing a sign that says; 'big boy go away, dis am home of mr h hog', up side down it reads 'Boy yew go away. We sip. Home of hog pig.' The protagonist asks the pig if it wants a big bun, upon which it replies 'Why big buns? Am mad u!', which flips into 'In pew we sang big hym'. Finally in ''The Bad Snake and the Good Wizard'' (1904 Mar 27) there are two more ambigrams. The first turns 'How do you do' into the name of a wizard called 'Opnohop Moy', the second features a squirrel telling the protagonist 'Yes further on' only to inform it that there are 'No serpents here' on his way back. In a 2012 Swedish remake of the book,<ref>{{cite book |last1=Ivarsson |first1=Marcus |title=Uppåner med lilla Lisen & gamle Muppen |date=2012 |publisher=Epix |isbn=978-91-7089-524-1}}</ref> the artist Marcus Ivarsson redraws ''The Bad Snake and the Good Wizard'' in his own style. He removes the squirrel, but keeps the other ambigram. 'How do you do' is replaced by 'Nejnej' (Swedish for no) and the wizard is now called 'Laulau'.

{{Commons and category inline|links=[[commons:Category:Ambigrams by Gustave Verbeek|Ambigrams by Gustave Verbeek]]}}.

[[Oubapo]], ''workshop of potential [[comic book art]]'', is a [[Comic book|comics]] movement which believes in the use of [[Formalism (art)|formal]] [[Constrained comics|constraints]] to push the boundaries of the medium. [[Étienne Lécroart]], [[cartoonist]], is a founder and key member of Oubapo association, and has composed cartoons that could be read either horizontally, vertically, or in diagonal, and vice versa, sometimes including appropriate ambigrams.<ref name="LecroartLarousse">{{Cite web|title=Étienne Lécroart|url=http://www.larousse.fr/encyclopedie/personnage/Étienne_Lécroart/184598|access-date=2021-08-07|website=Larousse|language=fr}}</ref>

{{clear}}

====Drawings and paintings====

{{multiple image
 | align = left
 | width = 180
 | image1 = Ambigram_¡OHO!_and_reversible_figures_drawn_by_Rex_Whistler,_1946,_up_and_down.jpg
 | caption1 = Ambigram "¡OHO!" published by [[Rex Whistler]] in 1946.
 | image2 = Ambigram_¡OHO!_and_reversible_figure_drawn_by_Rex_Whistler,_1946,_up_and_down.jpg
 | caption2 = Ambigram "¡OHO!" with [[reversible figure|reversible faces]] by [[Rex Whistler]] created before 1944. A young woman transforms into a grandmother.
}}

[[File:Me_we_co.jpg|thumb|Ambigram painting Me / We, horizontal axis mirror type (2007).]]

The British [[painter]], designer and illustrator [[Rex Whistler]], published in 1946 a rotational ambigram "¡OHO!" for the cover of a book gathering [[reversible figure|reversible drawings]].<ref name="RexWhistler">{{Cite web|title=Two illustrated by Rex Whistler|url=https://www.pbagalleries.com/view-auctions/catalog/id/436/lot/140618/iexcl-OHO-Certain-Two-faced-individuals-Now-Exposed-by-the-Bodley-Head|access-date=2021-08-07|website=PBA Galleries|language=en}}</ref>

The artist [[John Langdon (typographer)|John Langdon]], specialist of ambigrams,<ref name="Langdon2005" /> designed many color [[paintings]] featuring ambigrams of all kinds, figure-ground, rotational, mirror or totem. Among other influences, he particularly admires [[M. C. Escher]]'s [[drawings]].<ref>{{harvsp|Prokhorov|2013|p=11}}.</ref>

The Canadian artist Kelly Klages painted several [[Acrylic paint|acrylics]] on [[canvas]] with ambigram words and sentences referring to famous writers' novels written by [[William Shakespeare]] or [[Agatha Christie]], such as ''[[Third Girl]]'', ''[[The Tempest]]'', ''[[After the Funeral]]'', ''[[The Hollow]]'', Reformation, [[Sherlock Holmes]], and ''[[Elephants Can Remember]]''.<ref name="KellyKlages">{{Cite web|title=Ambigrams|url=https://winklerarts.com/exhibits/ambigrams/|access-date=2021-08-07|website=Winklerarts|language=en}}</ref>

{{clear}}

====Sculptures====

[[File:Ambigramme_OUI_NON_sculpture_anamorphosique_de_Markus_Raetz_2002.jpg|thumb|left|Ambigram ''OUI / NON'' (''Yes / No'', in French), by sculptor [[Markus Raetz]], installed at the top of a pole on the Place du Rhöne in [[Geneva]], [[Switzerland]], observed from two angles.]]

{{multiple image
 | direction = vertical
 | width = 220
 | header = [[Mia Florentine Weiss]]
 | image1 = GER_—_BY_–_Oberbayern_—_München_—_Prinzregentenstraße_3_("Love-Hate"-Skulptur)_2020.JPG
 | caption1 = "Love Hate" sculpture in [[Munich]], Germany, in 2020.
 | image2 = Mia_Florentine_Weiss_Now_Won_German_Reichstag_2017.jpg
 | caption2 = "Now / Won" installation in front of the [[Reichstag building]], [[Berlin]], Germany, 2017.
}}

The German [[conceptual art|conceptual]] artist [[Mia Florentine Weiss]] built a sculptural ambigram {{ill|Love Hate (sculpture)|lt=Love Hate|de|Love Hate}},<ref name="ArtNet">{{Cite web|title=German Artist Mia Florentine Weiss On Why Art Is Still The Barometer of Culture|url=https://news.artnet.com/partner-content/german-artist-mia-florentine-weiss-on-why-art-is-still-the-barometer-of-culture|access-date=2021-08-07|website=Artnet|date=2 June 2020 |language=en}}</ref> that has traveled Europe as a symbol of peace and change of perspective.<ref name="LoveHateGoogleArts">{{Cite web|title=The Two-Word Poem – Mia Florentine Weiss – Love/Hate|url=https://artsandculture.google.com/story/the-two-word-poem/tQUhBurRjRPaxg?hl=en|access-date=2021-08-07|website=Google Arts & Culture|language=en}}</ref> Depending on which side the viewer looks at it, the sculpture says "Love" or "Hate". A similar concept was installed in  front of the [[Reichstag building]] in [[Berlin]] with the words "Now / Won". Both sculptures are mirror type ambigrams, symmetrical around a vertical axis.<ref name="MiaMedium">{{Cite web|title="Europe — I love you"|url=https://medium.com/asoulforeurope/europe-i-love-you-9c37a8f4d2f3|access-date=2021-08-07|website=Medium|date=18 March 2019|language=en}}</ref>

The Swiss sculptor [[Markus Raetz]] made several three-dimensional ambigram works, featuring words generally with related meanings, such as
YES-NO (2003),<ref name="ArtnetRaetz">{{Cite web|title=Markus Raetz (Swiss, 1941–2020)|url=http://www.artnet.com/artists/markus-raetz/|access-date=2021-09-07|website=[[Artnet]]|language=en|archive-url=https://web.archive.org/web/20210210061354/http://www.artnet.com/artists/markus-raetz/|archive-date=2021-02-10}}</ref>
ME-WE (2004, 2010),<ref name="KunstmuseumbernRaetz">{{cite web |title=Markus Raets – Prints – Sculptures |url=https://www.kunstmuseumbern.ch/admin/data/hosts/kmb/files/page_editorial_paragraph_file/file_en/854/saaltext_raetz_e.pdf |website=[[Museum of Fine Arts Bern]] |language=en |access-date=2021-08-28|archive-url= https://web.archive.org/web/20200210164040/http://www.kunstmuseumbern.ch/admin/data/hosts/kmb/files/page_editorial_paragraph_file/file_en/854/saaltext_raetz_e.pdf?lm=1390979013 |archive-date= 2020-02-10}}.</ref>
OUI-NON (2000–2002) in French,<ref name="SikartRaetz">{{cite web |title=Raetz, Markus |url=https://www.sikart.ch/KuenstlerInnen.aspx?id=4000072 |website=[[SIKART]] |language=en |access-date=2021-08-28}}.</ref><ref name="GeneveRaetz">{{cite web |title=Œuvre OUI-NON |url=https://www.geneve.ch/fr/oeuvre-non |website=Geneve.ch |language=fr |access-date=2021-08-28|archive-url= https://web.archive.org/web/20210918035442/https://www.geneve.ch/fr/oeuvre-non |archive-date= 2021-09-18}}</ref>
SI–NO (1996)<ref name="SikartSiNo">{{cite web |title=Raetz, Markus, SI – NO |url=https://www.sikart.ch/Werke.aspx?id=12597961 |website=[[SIKART]] |language=en |access-date=2021-08-28|archive-url= https://web.archive.org/web/20210918100422/https://www.sikart.ch/Werke.aspx?id=12597961 |archive-date= 2021-09-18}}.</ref>
and TODO-NADA (1998) in Spanish<ref name="ChristiesTodo-Nada">{{cite web |title=Todo-Nada |url=https://www.christies.com/en/lot/lot-6212899 |website=[[Christie's]] |language=en |access-date=2021-08-28|archive-url= https://web.archive.org/web/20210918102716/https://www.christies.com/en/lot/lot-6212899 |archive-date= 2021-09-18}}.</ref><ref name="SikartTodoNada">{{cite web |title=Raetz, Markus TODO-NADA |url=https://www.sikart.ch/Werke.aspx?id=12599668 |website=[[SIKART]] |language=en |access-date=2021-08-28|archive-url= https://web.archive.org/web/20210918100739/https://www.sikart.ch/Werke.aspx?id=12599668 |archive-date= 2021-09-18}}.</ref>
These are [[Anamorphosis|anamorphic]] works, which change in appearance depending on the angle of view of the observer.
The OUI–NON ambigram is installed on the Place du Rhône, in [[Geneva]], [[Switzerland]], at the top of a metal pole. Physically, the letters have the appearance of iron twists. With the perspective, this work demonstrates that reality can be [[ambiguous]].<ref name="GeneveRaetz" />

Some ambigram sculptures by the French conjurer {{ill|Francis Tabary|lt=Francis Tabary|fr|Francis Tabary}} are reversible by a half-turn rotation, and can therefore be exhibited on a support in two different ways.<ref name="TabarySculptures">{{cite web |title=Sculptures ambigrammes |url=http://francistabary.fr/index.php?menu=sculptures_ambigrammes |website=Francis Tabary|language=fr |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210315023311/http://francistabary.fr/index.php?menu=sculptures_ambigrammes |archive-date= 2021-03-15}}.</ref><ref name="AmbigrammesTabary">{{cite web |title=Les sculptures impossibles de Francis Tabary |url=https://www.centpourcent-vosges.fr/culture/spectacle/les-sculptures-impossibles-de-francis-tabary/ |website=100% Vosges|date=4 September 2013 |language=fr |access-date=2021-08-28|archive-url= https://web.archive.org/web/20171209044228/https://www.centpourcent-vosges.fr/culture/spectacle/les-sculptures-impossibles-de-francis-tabary/ |archive-date= 2017-12-09}}.</ref>

====Tattoos====

{{multiple image
 | direction = vertical
 | align = left
 | width = 220
 | image1 = Ambigram_tattoo_Love_Eros.jpg
 | caption1 = Mirror ambigram [[tattoo]]s on wrists "Love / Eros".
 | image2 = Ambigram tattoo New York Rich Man.jpg
 | caption2 = Handmade ambigram in [[tattoo]] "[[New York City#Wealth and income disparity|New York / Rich Man]]", right side up and upside down.
}}

{{multiple image
 | direction = vertical
 | width = 220
 | image1 = Ambigram_tattoo_No_religion_(forearm).jpg
 | caption1 = 180° rotational ambigram [[tattoo]] "[[Irreligion|No religion]]".
 | image2 = Ambigram tattoo Texas Sexy.jpg
 | caption2 = Ambigram [[tattoo]] ''[[Texas#Arts|Texas]] / [[Sexual attraction|Sexy]]'', 180° rotational symmetry.
}}

One of the most dynamic sectors that harbors ambigrams is [[tattooing]]. Because they possess two ways of reading, ambigram tattoos inked on the skin benefit from a "mind-blowing" effect. On the arm, [[sleeve tattoo]]s [[point reflection|flip upside-down]], on the back or jointly on two wrists they are more striking with a [[axial symmetry|mirror symmetry]]. A large range of [[Calligraphy|scripts]] and [[font]]s is available. Experienced ambigram artists can create an [[optical illusion]] with a complex [[visual design]].<ref name="TattooDirectory">{{Cite book|url=https://books.google.com/books?id=o2Cr3tIU97QC&pg=PA106|title=Alphabets & Scripts Tattoo Design Directory: The Essential Reference for Body Art|last=Hemingson|first=Vince|publisher=Chartwell Books|year=2010|page=192|isbn=978-0-7858-2578-4|language=en}}</ref>

In 2015, an ambigram [[tattoo]] went [[viral phenomenon|viral]] following an [[advertising campaign]] developed by the [[Publicis]] group two years earlier. The ''[[Samaritans of Singapore]]'' organization, active in suicide prevention, has a 180° reversible "SOS" ambigram logo, [[acronym]] of its name and [[homonym]] of the famous [[SOS]] distress signal.
In 2013, this center orders advertisements that could be inserted in magazines to make readers aware of the problem of [[Depression (mood)|depression]] among young people, and the communication agency notices the symmetrical aspect of the logo. As a result, it begins to produce several ambigrammatic visuals, staged in photographic contexts, where sentences such as "I'm fine", "I feel fantastic" or "Life is great" turn into "Save me", "I'm falling apart", and "I hate myself". Readers noticing this logo placed at the upper left corner of the page with an upside-down typographical [[catchphrase]] rotate the newspaper and visualize the double calligraphed messages, which call out with the ''SOS''.<ref name="happinessCampaignCBC" /><ref name="SOSorg">{{cite web |title=World suicide prevention day 2014 - The hidden pain |url=https://www.sos.org.sg/campaign/world-suicide-prevention-day-2014 |website=[[Samaritans of Singapore]]|language=en |access-date=2021-09-20|archive-url= https://web.archive.org/web/20210926005618/https://www.sos.org.sg/campaign/world-suicide-prevention-day-2014 |archive-date= 2021-09-26}}.</ref>
These ads are so influential that Bekah Miles, an American student herself coming out of a severe depression, chooses to use the "I'm fine / Save me" ambigram to get a tattoo on her thigh. Posted on Facebook, the two-sided photography immediately appeals to many young people, impressed or sensitive to this difficulty.<ref name="HuffPostHiddenMessage">{{Cite web|title=Student Bekah Miles Gets Hidden Message 'I'm Fine Save Me' Tattoo To Force Herself To Talk About Her Depression|url=https://www.huffingtonpost.co.uk/2015/09/01/student-bekah-miles-hidden-message-im-fine-save-me-tattoo-depression_n_8069194.html|access-date=2021-08-07|website=[[HuffPost]]|language=en|date=2015-09-01|archive-url=https://web.archive.org/web/20210710115221/https://www.huffingtonpost.co.uk/2015/09/01/student-bekah-miles-hidden-message-im-fine-save-me-tattoo-depression_n_8069194.html|archive-date=2021-07-10}}</ref><ref name="SaveMeTattooPeople">{{cite web|title=Student's 'I'm Fine/Save Me' Tattoo Brings Depression Conversation to Light|url=https://people.com/celebrity/students-im-finesave-me-tattoo-sparks-conversation-about-depression/|access-date=2021-08-07|website=[[People (magazine)|People]]|language=en|date=2015-09-02|archive-url=https://web.archive.org/web/20180523010202/http://people.com/celebrity/students-im-finesave-me-tattoo-sparks-conversation-about-depression/|archive-date=2018-05-23}}</ref>
To educate its students, [[George Fox University]] in the United States then relays the optical illusion in its official journal, through a video totaling more than three million views<ref name="SaveMeTattooGFoxUniversity">{{cite web|title=I'm Fine... Save Me|url=https://www.georgefox.edu/journalonline/fall15/feature/bekah-miles.html|access-date=2021-08-07|website=[[George Fox University]]|language=en|date=2015-09-01|archive-url=https://web.archive.org/web/20210713111204/https://www.georgefox.edu/journalonline/fall15/feature/bekah-miles.html|archive-date=2021-07-13}}</ref> and the information is also reproduced in several local media and international organizations, thus helping to popularize this famous two-way tattoo.<ref name="SaveMeTattooOregonian">{{cite web|title=This Oregon student's tattoo is going viral because it helps explain depression|url=https://www.oregonlive.com/faith/2015/09/im_fine_tattoo.html|access-date=2021-08-07|website=[[The Oregonian]]|date=9 September 2015|language=en|archive-url=https://web.archive.org/web/20210906065810/https://www.oregonlive.com/faith/2015/09/im_fine_tattoo.html|archive-date=2021-09-06}}</ref><ref name="SaveMeTattooMetro">{{cite web|title=Tattoo brilliantly shows the battle people with depression face every day|url=https://metro.co.uk/2015/08/30/tattoo-brilliantly-shows-the-battle-people-with-depression-face-every-day-5368068/|access-date=2021-08-07|website=[[Metro (Associated Metro Limited)|Metro]]|language=en|date=2015-08-30|archive-url=https://web.archive.org/web/20170427133943/https://metro.co.uk/2015/08/30/tattoo-brilliantly-shows-the-battle-people-with-depression-face-every-day-5368068/|archive-date=2017-04-27}}</ref>
Less fortunate, another teenage girl, aged 16, committed suicide, with her also this ambigram found on a note in her room, "I'm fine / Save me", reversible calligraphy today printed on badges and bracelets, for educational purposes.<ref name="HelpMeBBC">{{cite web|title=Mental health: Girl's 'help me' note before death inspires mum|url=https://www.bbc.com/news/av/uk-england-nottinghamshire-49577791|access-date=2021-08-07|website=[[BBC]]|language=en|date=2019-09-05|archive-url=https://web.archive.org/web/20210511115227/https://www.bbc.com/news/av/uk-england-nottinghamshire-49577791|archive-date=2021-05-11}}</ref>

===Literature===

====Palindromes====

[[File:Ambigram Dogma I am god.png|thumb|left|Famous [[palindrome]] sentence "[[Dogma]] I am God" turned into a mirror ambigram. The [[Letter case|capital]] D at the left was changed into a lowercase d, and the [[Space (punctuation)|typographic spaces]] adjusted.]]

[[File:Ambigramme_de_Georges_Perec_-_andin_basnoda_a_une_epouse_qui_pue_-_animation.gif|thumb|[[Georges Perec]]'s "vertical [[palindrome]]" (rotational ambigram), in French.]]

Ambigrams are sorts of [[visual arts|visual]] [[palindromes]].<ref name="PolsterAmbigrammes">{{Cite book|title=Les Ambigrammes l'art de symétriser les mots|last=Polster|first=Burkard|publisher=Ecritextes|year=2003|language=fr}}</ref> Some words turn upside down, others are symmetrical through a mirror. Natural ambigram palindromes exist, like the words "wow", "[[malayalam]]"<ref name="Malayalam">{{Cite web|title=What Is The Longest Palindrome In English?|url=https://www.dictionary.com/e/palindromic-word/|access-date=2021-08-07|website=Dictionary|date=31 January 2020|language=en}}</ref> (Dravidian language), or the biotechnology company [[Noxxon]] that possesses a [[palindromic]] name associated to a rotational ambigram logo. But some words are natural ambigrams, though not palindromes in the literary acception, like "bud" for example, because b and d are different letters. As a result, some words and sentences are good candidates for ambigrammists, but not for palindromists, and reciprocally, since the [[Constrained writing|constraints]] differ slightly. Authors of ambigrams also benefit from a certain flexibility by playing on the [[typeface]] and [[graphic arts|graphical]] adjustments to influence the reading of their visual palindromes.

[[Oulipo]], ''workshop of potential literature'', seeks to create works using [[constrained writing]] techniques.<ref name="PotentialPlusUK" /> [[Georges Perec]], French novelist and member of the Oulipo group, designed a rotational ambigram, that he called "vertical palindrome".<ref name="PerecLiberation" /> Sibylline, the sentence "Andin Basnoda a une épouse qui pue" in French means "Andin Basnoda has a smelly wife". Perec did not care about punctuation spaces, but his [[Constrained writing|creation]] flips easily with a classical font like [[Arial]].

Visual palindromes sometimes perfectly illustrate literary contents. The American author [[Dan Brown]] incorporated [[John Langdon (typographer)|John Langdon]]'s designs into the plot of his bestseller ''[[Angels & Demons]]'', and his fictional character [[Robert Langdon]]'s surname was a homage to the [[John Langdon (typographer)|ambigram artist]].<ref name="WallStreetDaVinci">{{Cite news|title="The Da Vinci Code" Trial: Dan Brown's Witness Statement Is a Great Read|url=https://www.wsj.com/articles/BL-LB-808|access-date=2021-08-10|website=The Wall Street Journal|date=14 March 2006|language=en|last1=Lattman|first1=Peter}}</ref>

The fantasy novel [[Abarat]], written and illustrated by [[Clive Barker]], features an ambigram of the title on its cover.<ref name="AbaratGuardian">{{Cite web|title=Candy and Carrion|url=https://www.theguardian.com/books/2002/oct/19/sciencefictionfantasyandhorror.clivebarker|date=2002-10-19|access-date=2021-08-07|website=The Guardian|language=en}}</ref>

====Calligrams====

[[File:Ambigram_Good_ambigrams_human_face_calligram_design.png|thumb|left|[[Calligram]] "Good ambigrams" representing a [[face]] and mirror [[self-referential]] ambigram.]]

{{multiple image
 | width= 107
 | image1 = Alevisme.jpg
 | caption1 = Reflective [[calligram]] hat in [[Alevism]] forming a human [[face]] with [[Arabic alphabet|Arabic]] letters.
 | image2 = Oslo Klatreklubb logo.jpg
 | caption2 = [[Oslo]] Climbing Club official logo<ref name="OsloKlatreklubb" /> "{{ill|Oslo Klatreklubb|no|lt=OK|vertical-align=sup}}" ([[acronym]] for ''Oslo Klatreklubb'') 90° rotational ambigram showing a human [[silhouette]] vertically.
}}

A [[calligram]] is text arranged in such a way that it forms a thematically related image. It can be a poem, a phrase, a portion of [[scripture]], or a single word. The visual arrangement can rely on certain use of the [[typeface]], [[calligraphy]] or [[handwriting]]. The image created by the words illustrates the text by expressing visually what it says, or something closely associated.

In [[Islamic calligraphy]], symmetrical calligrams appear in ancient and modern periods, forming mirror ambigrams in [[Arabic alphabet|Arabic]] language.<ref name="Crosbi" />

The word "[[OK]]" turned 90° [[counterclockwise]] evokes a human icon, with the letter O forming the head and the letter K the arms and the legs. The Norwegian Climbing Club {{ill|Oslo Klatreklubb|lt=Oslo Klatreklubb|no|Oslo Klatreklubb}} ([[acronym]] "OK") borrowed the concept of this natural [[calligram]] for their official logo.<ref name="OsloKlatreklubb">{{Cite web|title=Oslo Klatreklubb|url=https://osloklatreklubb.no/|access-date=2021-08-07|website=OsloKlatreklubb|language=no}}</ref>

{{clear}}

====Semantics====

[[File:Ambigramme_Lapin_Rabbit.png|thumb|left|[[Bilingual]] mirror ambigram playing on the [[translation]] of the word "[[:wikt:lapin#Noun 3|Lapin]]" (''[[rabbit]]'', in French).]]

[[File:Ambigram here away.png|thumb|[[Self-referential]] [[Composition (visual arts)|composition]] "here / away" displayed in a spiral to express distance, thus enhancing the [[Language interpretation|meaning]]. ]]

As described by [[Douglas Hofstadter]], ambigrams are [[visual pun]]s having two or more (clear) [[Interpretation (philosophy)|interpretations]] as [[written word]]s.<ref name="polster" />

[[Multilingual]] ambigrams can be read one way in a [[language]], and another way in a different language or [[alphabet]].<ref name="AmbigramTypes">{{harvsp|Prokhorov|2013|p=112}}.</ref>
Multi-lingual ambigrams can occur in all of the various types of ambigrams, with multi-lingual perceptual shift ambigrams being particularly striking.

Like certain [[anagram]]s with providential meanings such as "Listen / Silent" or "The eyes / They see", ambigrams also sometimes take on a timely sense, for example "up" becomes the abbreviation "dn", very naturally by rotation of 180°.<ref name="GardnerColossalBook">{{Cite book|title=The Colossal Book of Mathematics: Classic Puzzles, Paradoxes, and Problems|url=https://books.google.com/books?id=orz0SDEakpYC&q=colossal+book+of+mathematics+gardner|first=Martin|last=Gardner|author-link=Martin Gardner|publisher=[[W. W. Norton & Company]]| edition=1st|year=2001|page=736|isbn = 978-0-393-02023-6|language=en}}</ref>
But on the other hand, it happens that the luck of the letters makes things bad. This is the case with the weird anagram "[[Santa]] / Satan", as it is with a rotational ambigram that has gone [[viral phenomenon|viral]] because of the [[paradox]]ical and unintentional message it expresses. Spotted in 2015 on a metal medal marketed without bad intention, the text "[[hope]]" displays upside down with a fairly obvious reading "[[Adolf Hitler|Adolf]]". This coincidence photographed by an Internet user was relayed by several media and constitutes an [[ambiguous image]].<ref name="DailyMirrorHope">{{cite web |title=Can you spot what's wrong with this badge? |url=https://www.mirror.co.uk/news/weird-news/can-you-spot-whats-wrong-6323793 |website=[[The Daily Mirror]] |language=en |access-date=2021-09-20|date = 2015-08-26| archive-url= https://web.archive.org/web/20150828182514/https://www.mirror.co.uk/news/weird-news/can-you-spot-whats-wrong-6323793 |archive-date= 2015-08-28}}.</ref><ref name="DailyExpressHope">{{cite web |title=Can YOU see the shocking secret this 'Hope' badge is hiding? |url=https://www.express.co.uk/life-style/life/601094/Badge-hope-shocking-secret-Adolf-Hitler |website=[[Daily Express]] |language=en |access-date=2021-09-20| date = 2015-08-28| archive-url= https://web.archive.org/web/20151101052904/http://www.express.co.uk/life-style/life/601094/Badge-hope-shocking-secret-Adolf-Hitler |archive-date= 2015-11-01}}.</ref>

{{clear}}

===Mathematics===

[[File:91=90+01wiki.jpg|thumb|Ambigram of a reversible [[arithmetic]] operation.]]

[[Recreational mathematics]] is carried out for [[entertainment]] rather than as a strictly research and application-based professional activity.<ref name="RecreaMathsNYT" /> An ambigram [[magic square]] exists, with  the sums of the numbers in each row, each column, and both main diagonals the same right side up and upside down (180° rotational design). Numeral ambigrams also associate with alphabet letters. A "dissection" ambigram of "[[squaring the circle]]" was achieved in a puzzle where each piece of the word "circle" fits inside a perfect square.<ref name="polster" />

[[Burkard Polster]], professor of mathematics in [[Melbourne]]<ref>{{citation|url=https://research.monash.edu/en/persons/burkard-polster|title=Burkard Polster|publisher=Monash University|work=Faculty profiles|access-date=23 January 2018}}</ref> conducted researches on ambigrams and published several books dealing with the topic, including ''Eye Twisters, Ambigrams & Other Visual Puzzles to Amaze and Entertain''.<ref name="Polster2007">{{harvsp|Polster|2007}}.</ref> In the abstract ''Mathemagical Ambigrams'', Polster performs several ambigrams closely related to his realm, like the words "[[algebra]]", "[[geometry]]", "[[math]]", "[[maths]]", or "mathematics".<ref name="polster" />

{| class="wikitable"
|{{7seg|h|12px}}{{7seg|E|12px}}{{7seg|L|12px}}{{7seg|L|12px}}{{7seg|O|12px}}
|-
|Message written with the [[Numerical digit|digits]] "07734" upside down.
|}

[[Calculator spelling]] is an [[Unintended consequences|unintended characteristic]] of the [[seven-segment display]] traditionally used by [[calculator]]s, in which, when read upside-down, the digits resemble letters of the [[Latin alphabet]]. Also, [[palindromic numbers]] and [[strobogrammatic number]]s sometimes attract attention of mathematician ambigrammists.<ref name=Britannica /><ref name="BritannicaStrobo" />

Ambigram [[tessellation]]s and [[3D modeling|3D]] ambigrams are two types particularly fun for the mathematician in [[geometry]]. Word [[pattern]]s in tessellations can start from 35 different fundamental [[polygons]], such as the [[rhombus]], the [[isosceles]] [[right triangle]], or the [[parallelogram]].<ref name="AlainNicolasBnF" />

[[Word puzzle]]s are used as a source of [[entertainment]], but can additionally serve an [[education]]al purpose. The American [[puzzle]] designer [[Scott Kim]] published several ambigrams in ''[[Scientific American]]'' in [[Martin Gardner]]'s
"[[List of Martin Gardner Mathematical Games columns|Mathematical Games]]" column, among them long sentences like ''"Martin Gardner's celebration of [[mind]]"'' turning into "Physics, patterns and [[prestidigitation]]".<ref>{{harvsp|Prokhorov|2013|p=34}}.</ref>

===Psychology===

[[File:Ambigram Ambiguity.png|thumb|"Ambiguity", 180° rotational ambigram.]]

[[Legibility]] is an important aspect in successful ambigrams. It concerns the ease with which a reader decodes symbols. If the message is lost or difficult to perceive, an ambigram does not work.<ref name="Adobe" /> Readability is related to [[perception]], or how our brain [[interprets]] the forms we see through our eyes.<ref name="GraphicalArtNews">{{Cite web|title=Ambigram. How to design it?|url=https://www.graphicart-news.com/ambigram-how-to-design-it/#.YRcf2IgzaUk|date=2012-03-12|access-date=2021-08-07|website=Graphical art news|language=en}}</ref>

[[Symmetry]] in ambigrams generally improves the visual appearance of the [[calligraphic]] words.<ref name="Prokhorov2013" /> [[Hermann Rorschach]], inventor of the [[Rorschach Test]] notices that asymmetric figures are rejected by many subjects. Symmetry supplies part of the necessary artistic composition.<ref name="Rorschach">{{Cite book|title=Psychodiagnostics A Diagnostic Test Based On Perception|url=|last=Rorschach|first=Hermann|isbn=978-1-297-49635-6|publisher=Andesite Press|year=2015|page=274|language=en}}</ref>

For many [[amateur]]s, designing ambigrams represents a [[recreational activity]], where [[serendipity]] can play a fertile role, when the author makes an unplanned fortunate discovery.<ref name="polster" /><ref name="TheStrandMagazinePage359" />

====Duality and analogy====

[[File:U%2B262F.svg|upright=0.3|thumb|left|[[Yin and yang]] symbol, concept of [[Dualistic cosmology|dualism]].]]

[[File:Ambigram Two in One (animated).gif|thumb|"Two in one", half-turn ambigram.]]

In the word "''ambigram''", the root ''ambi-'' means "both" and is a popular prefix in a [[Dualistic cosmology|world of dualities]], such as day/night, left/right, birth/death, good/evil.<ref>{{harvsp|Prokhorov|2013|p=40}}.</ref> In ''Wordplay: The Philosophy, Art, and Science of Ambigrams'',<ref>{{harvsp|Langdon|2005|pp=6–16}}.</ref> [[John Langdon (typographer)|John Langdon]] mentions the [[yin and yang]] symbol as one of his major influences to create upside down words.

Ambigrams are mentioned in ''[[Metamagical Themas]]'', an eclectic collection of articles that [[Douglas Hofstadter]] wrote for the [[popular science]] magazine ''[[Scientific American]]'' during the early 1980s.<ref name="MetamagicalThemas">{{Cite book|title=Metamagical Themas: Questing For The Essence Of Mind And Pattern|url=https://archive.org/stream/MetamagicalThemas/Metamagical%20Themas,%20Hofstadter_djvu.txt|last=Hofstadter|first=Douglas|isbn=978-0-7867-2386-7|publisher=Basic Books|year=2008|page=880|language=en}}</ref>

{{Blockquote
|text=Seeking the balance point of [[analogies]] is an [[aesthetic]] exercise closely related to the aesthetically pleasing activity of doing ambigrams, where shapes must be concocted that are poised exactly at the midpoint between two [[Interpretation (philosophy)|interpretation]]s. But seeking the balance point is far more than just aesthetic play; it probes the very core of how people perceive [[abstraction]]s, and it does so without their even knowing it. It is a crucial aspect of [[Copycat (software)|Copycat]] research.<ref name="MetamagicalThemas" />
|author=[[Douglas Hofstadter]]
}}

===Magic===

[[File:Ambigram_Real_world_Prank_Fake_rainbow_animated_(2).gif|thumb|left|upright|"[[The Real World (TV series)|Real world]] / [[Prank]] [[Illusion|Fake]]", ambigram expressing [[illusion]].]]

{{multiple image
| width             = 180
| image1            = Ambigram Magic Dream - mirror symmetry with a handheld pattern giving a reversed shadow on a blue wall.jpg
| caption1          = Ambigram "[[Magic (illusion)|Magic]] / [[Dream]]", with a handheld pattern giving a reversed shadow.
| image2            = Ambigram incredible! (orange and indigo) - animated.gif
| caption2          = "[[wikt:incredible|incredible]]!" Magical ambigram.<ref name="Superinteressante">{{Cite web|url=https://super.abril.com.br/cultura/palindromos-e-ambigramas-por-que-a-data-22-02-2022-e-tao-especial/|website=[[Superinteressante]]|title=Palíndromos e ambigramas: por que a data 22/02/2022 é tão especial?|date=2022-02-22|first=Luisa|last=Costa|language=pt|archive-url=https://web.archive.org/web/20220723035619/https://super.abril.com.br/cultura/palindromos-e-ambigramas-por-que-a-data-22-02-2022-e-tao-especial/|archive-date=2022-07-23|access-date=2022-11-10}}</ref>
}}

In [[magic (illusion)|magic]], ambigrams work like [[visual illusions]], revealing an unexpected new message from a particular written word.<ref name="MastersOfDeception">{{Cite book|title=Masters of Deception: Escher, Dalí & the Artists of Optical Illusion|url=https://books.google.com/books?id=t5IgWas4rJwC&pg=PA312|last=Seckel|first=Al|publisher=Sterling|year=2017|page=320|isbn = 978-1-4027-0577-9|language=en}}</ref>

In the first series of the British show ''[[Trick or Treat (TV series)|Trick or Treat]]'', the show's host and creator [[Derren Brown]] uses cards with rotational ambigrams.<ref name="DerrenBrowninfo">{{Cite web|title=TV Series – Derren Brown: Trick or Treat|url=http://www.derrenbrowninfo.co.uk/programmes/tv-series-derren-brown-trick-treat/|access-date=2021-08-07|website=Derren Brown info|language=en}}</ref><ref>{{Cite web|url=http://www.johnlangdon.net/images/may11_07_1b.jpg|archive-url=https://web.archive.org/web/20080925194248/http://www.johnlangdon.net/images/may11_07_1b.jpg|title=Johnlangdon.net|archive-date=September 25, 2008}}</ref> These cards can read either 'Trick' or 'Treat'.

[[Ambiguous image]]s, of which ambigrams are a part, cause ambiguity in different ways. For example, by rotational symmetry, as in the Illusion of ''[[The Cook (Arcimboldo)|The Cook]]'' by [[Giuseppe Arcimboldo]] (1570);<ref name="WGAArcimboldo">{{cite web |title=Composite and reversible heads by Giuseppe ARCIMBOLDO |url=https://www.wga.hu/html_m/a/arcimbol/4composi/index.html |website=[[Web Gallery of Art]] |language=en |access-date=2021-08-28|archive-url=https://web.archive.org/web/20210828125713/https://www.wga.hu/html_m/a/arcimbol/4composi/index.html|archive-date=2021-08-28}}.</ref> sometimes by a [[Figure–ground (perception)|figure-ground]] ambivalence as in [[Rubin vase]]; by perceptual shift as in the [[rabbit–duck illusion]], or through [[pareidolia]]s; or again, by the representation of [[impossible object]]s, such as [[Necker cube]] or [[Penrose triangle]]. For all these types of images, certain ambigrams exist, and can be combined with [[visuals]] of the same type.

[[John Langdon (typographer)|John Langdon]] designed a [[figure-ground (perception)|figure-ground]] ambigram "[[optical illusion]]" with the two words "optical" and "illusion", one forming the figure and the other the background. "Optical" is easier to see initially but "illusion" emerges with longer observation.<ref name="LangdonIllusion">{{Cite book|title=Art and Illusionists|url=https://books.google.com/books?id=hAO5CgAAQBAJ&pg=PA180|last=Wade|isbn=978-3-319-25229-2|first=Nicholas|publisher=Springer|year=2016|page=398|language=en}}</ref>

===Manufacturing===

====Clothing and fashion====

[[File:Ambigram Bounce, Adidas pink shoe - animated.gif|thumb|Ambigram "Bounce", printed inside a pink [[Adidas]] shoe.]]

[[Adidas]] marketed a line of [[sneakers]] called "Bounce", with an ambigram [[typography]] printed inside the shoe.

Several clothing brands, such as [[Helly Hansen]] (HH), [[Under Armour]] (UA), or {{ill|New Man (clothing)|lt=''New Man''|fr|New Man}}, raise an ambigram logo as their visual [[corporate identity|identity]].<ref name="NewManLJDN" />

Mirror ambigrams are also sometimes placed on [[T-shirt]]s, [[towel]]s and [[hat]]s, while [[sock]]s are more adapted to rotational ambigrams. The [[conceptual art|conceptual]] artist [[Mia Florentine Weiss]] marketed T-shirts and other products with her mirror ambigram {{ill|Love Hate (sculpture)|lt=Love Hate|de|Love Hate}}.<ref name="LoveHateProducts">{{Cite web|title=Love Hate|url=https://love-hate.org/new-products|access-date=2021-08-07|website=Love Hate|language=en|archive-date=2021-08-13|archive-url=https://web.archive.org/web/20210813124317/https://love-hate.org/new-products|url-status=dead}}</ref><ref name="LoveHateGoogleArts" />
Likewise, the city of [[Ventura, California|Ventura]] in California sells sweatshirts, caps, jackets, and other fashion accessories printed with its rotational ambigram logo.<ref name="ShopVentura">{{cite web |title=Farewell Summer, Hello Fall |url=https://shop.visitventuraca.com/collections/back-to-school-ventura-style |website=VisitVenturaCa.com |language=en |access-date=2021-09-27|archive-url= https://web.archive.org/web/20210927034500/https://shop.visitventuraca.com/collections/back-to-school-ventura-style |archive-date= 2021-09-27}}.</ref>

<gallery mode="packed" class="center">
File:Ambigram_Ideal,_polysymmetrical_logo_printed_on_a_green_T-shirt.jpg|Rotational and reflective ambigram "Ideal", [[Printed T-shirt|printed]] on a T-shirt.
File:Ambigram Zen Yes text with meditation pictogram, embroidered on a blue T-shirt.jpg|"[[Zen]] Yes" embroidered on a blue T-shirt with a meditation symmetrical [[pictogram]].
File:Helly_Hansen_H%27s_(3887766452).jpg|[[Helly Hansen]], [[Norway|Norwegian]] manufacturer and retailer of [[clothing]] and sports equipment, has an ambigram logo.
</gallery>

====Accessories====

[[File:Ambigram Cognac Danger on a set of two shot glasses (empty and full).jpg|thumb|"[[Cognac]] / [[Health effects of alcohol|Danger]]", front and back, on a set of two [[shot glass]]es. Humorous warning related to [[Health effects of alcohol|alcohol consumption]].]]

The [[CD cover]] of the thirteenth studio album [[Funeral (Lil Wayne album)|''Funeral'']] by American rapper [[Lil Wayne]] features a 180° rotational ambigram reading "Funeral / Lil Wayne".<ref name="FuneralLilWayne">{{cite magazine |title=Lil Wayne releases his 13th album, Funeral |url=https://ew.com/music/2020/01/31/lil-wayne-releases-13th-album-funeral/ |magazine=Entertainment Weekly |access-date=April 16, 2020 |archive-url=https://web.archive.org/web/20200409172257/https://ew.com/music/2020/01/31/lil-wayne-releases-13th-album-funeral/ |archive-date=April 9, 2020 |url-status=live }}</ref>

The [[Special edition#Music|special edition]] paper sleeve (CD with DVD) of the solo album [[Chaos and Creation in the Backyard]] by [[Paul McCartney]] features an ambigram of the singer's name.<ref name="AmbigramMcCartney">{{Cite tweet| name = Paul McCartney | user = PaulMcCartney | lang = en | title = Did you know the album artwork for 'Chaos and Creation in the Backyard' features Paul's name styled as an ambigram. Is it Paul McCartney or ʎǝuʇɹɐƆɔW lnɐԀ?| date = 2018-05-25| number = 1000006420987830274| archive-url = https://web.archive.org/web/20210815061030/https://twitter.com/paulmccartney/status/1000006420987830274 | archive-date = 2021-08-15| url-status = live }}</ref>

The [[Grateful Dead]] have used ambigrams several times, including on their albums ''[[Aoxomoxoa]]''<ref>{{cite book
 | last = Davis | first = Erik
 | editor-last = Odorisio | editor-first = David M.
 | contribution = The Flying Eyeball: The Mythopoetics of Rick Griffin
 | doi = 10.1007/978-3-031-20127-1_5
 | isbn = 9783031201271
 | pages = 83–111
 | publisher = Springer International Publishing
 | title = A New Gnosis: Comic Books, Comparative Mythology, and Depth Psychology
 | year = 2023}} See p. 88.</ref> and ''[[American Beauty (album)|American Beauty]]''.<ref>{{cite book
 | last = Smolko | first = Tim
 | isbn = 9780253010384
 | page = 33
 | publisher = Indiana University Press
 | title = Jethro Tull's Thick as a Brick and A Passion Play: Inside Two Long Songs Profiles in Popular Music
 | url = https://books.google.com/books?hl=en&lr=&id=6UfFAAAAQBAJ&pg=PA33
 | year = 2013}}</ref>

Although the words spelled by most ambigrams are relatively short in length, one [[DVD]] cover for [[The Princess Bride (film)|''The Princess Bride'']] movie creates a rotational ambigram out of two words "Princess Bride", whether viewed right side up or upside down.<ref name="WiredPrincess">{{Cite magazine|title=Princess Bride Ambigram|url=https://www.wired.com/2009/01/princess-bride/|date=2009-01-14|access-date=2021-08-10|magazine=Wired|language=en}}</ref>

The cover of the studio album ''[[Create/Destroy/Create]]'' by rock band [[Goodnight, Sunrise]] is an ambigram composition constituted of two invariant words, "create" and "destroy", designed by Polish artist Daniel Dostal.<ref name="CreateDestroy">{{Cite web|url=https://daneel75.wordpress.com/2013/03/13/create-destroy-create-ambigram/|title=Create / Destroy / Create – ambigram|date=2013-03-13|website=Signum et imago|access-date=2021-08-15}}</ref>

The reversible [[shot glass]] containing a changing message "Drink / Drunk", created by the [[typographer]] [[Mark Simonson]] was manufactured and sold in the market.<ref name="DrinkDrunk" />

The concept of reversible sign that some merchants use through their windows to indicate that the store is sometimes "open", sometimes "closed", was inaugurated at the beginning of the 2000s, by a rotational ambigram "Open / Closed" developed by David Holst.<ref name="PourLaScience" />

==Creation==

[[File:Ambigram_Escher_and_tessellation_background_-_photomontage_with_reversible_hands.jpg|thumb|Ambigram and [[tessellation]] "Escher", handmade design.]]
Different ambigram [[artist]]s, sometimes called ''ambigrammists'',<ref name="MetamagicalThemas" /><ref>{{harvsp|Prokhorov|2013|p=vi}}.</ref> may create distinctive ambigrams from the same words, differing in both [[Style (visual arts)|style]] and [[Elements of art#Form|form]].

===Handmade designs===

There are no universal guidelines for creating ambigrams, and different [[Problem solving|ways]] of approaching problems coexist.
A number of books suggest [[Scientific method|methods]] for [[Creativity|creation]], including ''WordPlay'',<ref name="Langdon2005" /> ''Eye Twisters'',<ref name="Polster2007" /> and ''Ambigrams Revealed'',<ref name="Prokhorov2013" /> in English.

===Generators===

[[Computer program|Computerized]] methods to [[Automation|automatically]] create ambigrams have been developed.<ref>{{cite conference
 | last = Loviscach | first = Jörn
 | editor1-last = Lensch | editor1-first = Hendrik P. A.
 | editor2-last = Seipel | editor2-first = Stefan
 | contribution = Finding approximate ambigrams and making them exact
 | doi = 10.2312/egsh.20101039
 | pages = 25–28
 | publisher = Eurographics Association
 | title = 31st Annual Conference of the European Association for Computer Graphics, Eurographics 2010 – Short Papers, Norrköping, Sweden, May 3–7, 2010
 | year = 2010}}</ref><ref>{{cite conference
 | last1 = Shirakawa | first1 = Takahiro
 | last2 = Uchida | first2 = Seiichi
 | arxiv = 2306.12049
 | editor1-last = Fink | editor1-first = Gernot A.
 | editor2-last = Jain | editor2-first = Rajiv
 | editor3-last = Kise | editor3-first = Koichi
 | editor4-last = Zanibbi | editor4-first = Richard
 | contribution = Ambigram generation by a diffusion model
 | doi = 10.1007/978-3-031-41682-8_20
 | pages = 314–330
 | publisher = Springer
 | series = Lecture Notes in Computer Science
 | title = Document Analysis and Recognition – ICDAR 2023 – 17th International Conference, San José, CA, USA, August 21–26, 2023, Proceedings, Part III
 | volume = 14189
 | year = 2023}}</ref>

===Artists===

[[John Langdon (typographer)|John Langdon]] and [[Scott Kim]] each believed that they had invented ambigrams in the 1970s.<ref name="Doodle">{{cite news|url=https://www.telegraph.co.uk/culture/3648509/The-doodle-bug.html |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/culture/3648509/The-doodle-bug.html |archive-date=2022-01-12 |url-access=subscription |url-status=live|title=The Doodle Bug|first=Emily|date=4 December 2005|newspaper=[[The Daily Telegraph|The Telegraph]]|author=Bearn|access-date=6 November 2016}}{{cbignore}}</ref>

====Douglas Hofstadter====

[[File:Rainbow reflection ambigram.jpg|thumb|upright|[[Douglas Hofstadter]]'s mirror ambigrams featuring the names of the seven [[rainbow]] colors, followed by a complex perceptual shift ambigram "2006" / "Doug", fusion of his signature and the date.]]

[[Douglas Hofstadter]] coined the term.<ref name="polster" />

To explain visually the numerous types of possible ambigrams, Hofstadter created many pieces with different constraints and symmetries.<ref>{{harvsp|Hofstadter|1986}}.</ref> Hofstadter has had several exhibitions of his artwork in various university galleries.<ref name="WilliamsCollege">{{Cite web|title=Douglas Hofstadter - "A Tale of Luck and of Pluck: The Fortuitous Discovery, Forty-two Years Ago, of the Hofstadter Butterfly"|url=https://csci.williams.edu/douglas-hofstadter-a-tale-of-luck-and-of-pluck-the-fortuitous-discovery-forty-two-years-ago-of-the-hofstadter-butterfly/|access-date=2023-09-06|archiveurl=https://web.archive.org/web/20230903182628/https://csci.williams.edu/douglas-hofstadter-a-tale-of-luck-and-of-pluck-the-fortuitous-discovery-forty-two-years-ago-of-the-hofstadter-butterfly/|archivedate=2023-09-03|website=[[Williams College]]|language=en}}</ref><ref name="HofstadterKimIndiana">{{Cite web|title=How to create an ambigram|url=https://cogsci.indiana.edu/lectures/SEKtalk/|access-date=2023-09-06|archiveurl=https://web.archive.org/web/20230906093321/https://cogsci.indiana.edu/lectures/SEKtalk/|archivedate=2023-09-06|website=[[Indiana University Bloomington|Indiana University]]|language=en}}</ref>

According to [[Scott Kim]], Hofstadter once created a series of 50 ambigrams on the name of all the states in the US.<ref>{{harvsp|Prokhorov|2013|p=34|id=AmbigramsRevealed}}.</ref>

In 1987 a book of 200 of his ambigrams, together with a long dialogue with his alter ego Egbert G. Gebstadter on ambigrams and [[creativity]], was published in Italy.<ref name="HofstadterIndiana" /><ref name="harvsp|Polster|2007|p=198"/>

====John Langdon====

[[John Langdon (typographer)|John Langdon]] is a [[self-taught]] [[artist]], [[graphic design]]er and [[painter]], who started designing ambigrams in the late 1960s and early 70s. [[Lettering]] specialist, Langdon is a professor of [[typography]] and [[corporate identity]] at [[Drexel University]] in [[Philadelphia]].<ref name="CitypaperLangdon">{{Cite web|title=Wordsmith John Langdon and the art of the ambigram. |url=http://citypaper.net/articles/2005-11-17/cover5.shtml |access-date=2021-08-07|website=Citypaper|archive-url=https://web.archive.org/web/20080724231839/http://citypaper.net/articles/2005-11-17/cover5.shtml |archive-date=2008-07-24 |language=en}}</ref>

John Langdon produced a mirror image logo "Starship" in 1972-1973,<ref name="StarshipLangdon">{{Cite web|url=http://www.johnlangdon.net/works/starship/|title=Starship|last=Langdon|first=John|website=johnlangdon.net|publisher=[[John Langdon (typographer)|John Langdon]]|access-date=6 November 2016}}</ref><ref>{{harvsp|Polster|2007|p=10}}.</ref> that was sold to the rock band [[Jefferson Starship]].

Langdon's ambigram book ''Wordplay'' was published in 1992. It contains about 60 ambigrams. Each design is accompanied by a brief essay that explores the word's definition, its etymology, its relationship to philosophy and science, and its use in everyday life.<ref name="Langdon2005" />

Ambigrams became more popular as a result of [[Dan Brown]] incorporating John Langdon's designs into the plot of his bestseller, ''[[Angels & Demons]]'', and the DVD release of the ''[[Angels & Demons (film)|Angels & Demons]]'' movie contains a bonus chapter called "This is an Ambigram".  Langdon also produced the ambigram that was used for some versions of the book's cover.<ref name="Doodle"/> Brown used the name [[Robert Langdon]] for the hero in his novels as an homage to John Langdon.<ref name="WallStreetDaVinci" /><ref name="TheNewYorkTimesAmbigram" />

[[Blacksmith Records]], the music management company and [[record label]], possesses a rotational ambigram logo<ref name="Blacksmith">{{Cite web|title=Blacksmith home page|url=https://blacksmithnyc.com/|access-date=2021-08-07|website=blacksmithnyc|language=en}}</ref> designed by John Langdon.<ref name="BlacksmithLangdon">{{Cite web|title=Blacksmith John Langdon|url=https://www.johnlangdon.net/works/blacksmith/|access-date=2021-08-16|website=John Langdon|language=en|archive-url=https://web.archive.org/web/20220121024955/https://www.johnlangdon.net/works/blacksmith/|archive-date=2022-01-21}}</ref>

====Scott Kim====

[[Scott Kim]] is one of the best-known masters of the art of ambigrams.<ref name="Wired" /> He is an American [[puzzle]] designer and [[artist]] who published in 1981 a book called ''Inversions'' with ambigrams of many types.<ref name="Kim1986" /><ref name="TheNewYorkTimesAmbigram">{{Cite web|title=Wow, Mom: It's an Ambigram!|date=2011-04-07|url=https://cityroom.blogs.nytimes.com/2011/04/07/wow-mom-its-an-ambigram/|access-date=2021-08-07|website=[[The New York Times]]|language=en|archive-url= https://web.archive.org/web/20201222015543/https://cityroom.blogs.nytimes.com/2011/04/07/wow-mom-its-an-ambigram/ |archive-date=2020-12-22}}</ref>

====Other====

[[Nikita Prokhorov (graphic artist)|Nikita Prokhorov]] is a [[graphic designer]], [[lettering artist]] and ambigram designer. His book ''Ambigrams Revealed'' showcases ambigram designs of all types, from all around the world.<ref name="Prokhorov2013" /><ref name="NikitaLogoLounge">{{Cite web|title=Center Stage: Nikita Prokhorov|url=https://www.logolounge.com/articles/center-stage-nikita-prokhorov|access-date=2021-08-07|website=Logolounge|language=en}}</ref>

Born in 1946, [[Alain Nicolas]] is a specialist of figurative and ambigram [[tessellation]]s. In his book, he performed many tilings with various words like "infinity", "[[Einstein]]" or "inversion" legible in many orientations.<ref name="AlainNicolasBnF" /> According to ''[[The Guardian]]'', Nicolas has been called "the world's finest artist of [[M.C. Escher|Escher]]-style [[tessellation|tilings]]".<ref name="AlainNicolasGuardian">{{Cite web|title=Can you solve it?|url=https://www.theguardian.com/science/2019/feb/11/can-you-solve-it-on-the-tiles-with-the-new-escher|access-date=2021-08-07|website=The Guardian|date=11 February 2019|language=en}}</ref>

==References==
{{Reflist}}

==Bibliography==
<!-- Refs are in chronological order -->

*{{Cite book |last=Hofstadter|first=Douglas|author-link=Douglas Hofstadter|title=Les Ambigrammes: Ambiguïté, Perception, et Balance Esthétique|publisher=Castella|year=1986|pages=157–187|language=fr|url=https://www.cogsci.indiana.edu/phard.html}}
*{{cite book |last=Hofstadter|first=Douglas|author-link=Douglas Hofstadter|title=Ambigrammi. Un microcosmo ideale per lo studio della creatività |language=it| publisher=Hopefulmonster |year=1987|isbn=978-88-7757-006-2}}
*{{cite book |last=Kim |first=Scott |author-link=Scott Kim|title=Inversions: A Catalog of Calligraphic Cartwheels |publisher=Byte Books |orig-date=1981 |year=1986|isbn=978-0-07-034546-1 |url-access=registration |url=https://archive.org/details/inversionscatalo00kims}}
*{{cite book |last=Langdon |first=John |author-link=John Langdon (typographer)|title=Wordplay: The Philosophy, Art, and Science of Ambigrams |year=2005|orig-date=1992-03-03 |publisher=Bantam Press |isbn= 978-0-593-05569-4}}
*{{Cite book |last=Prokhorov |first=Nikita |title=Ambigrams Revealed: A Graphic Designer's Guide To Creating Typographic Art Using Optical Illusions, Symmetry, and Visual Perception |publisher=New Riders|year=2013|isbn=978-0-13-308646-1|language=en|url=https://books.google.com/books?id=dWTaRp2-HDUC&pg=PT1}}
*{{cite book |last=Polster |first=Burkard |author-link=Burkard Polster |title=Eye Twisters|year=2007 |publisher=Constable |isbn=978-1-4027-5798-3}}

==Further reading==
<!-- Refs are in chronological order -->
* [[Hofstadter, Douglas R.]], "Metafont, Metamathematics, and Metaphysics: Comments on Donald Knuth's Article 'The Concept of a Meta-Font'"  ''Scientific American'' (August 1982) (republished, with a postscript, as chapter 13 in the book ''[[Metamagical Themas]]'' {{ISBN|978-0-553-34683-1}})
*{{cite book |last=Langdon |first=John |author-link=John Langdon (typographer) |title=La philosophie, l'art et la science des ambigrammes |year=2006 |publisher=Éditions Jean-Claude Lattès |isbn= 978-2-709-62855-6 |language=fr}}
* {{cite book |last=Polster |first=Burkard |author-link=Burkard Polster |title=Les Ambigrammes l'art de symétriser les mots |publisher=Ecritextes |year=2003 |isbn=978-2-9156-3300-9| language=fr}}

==External links==
{{sister project links|d=Q221552|commons=Category:Ambigrams|q=no|n=no|v=no|s=no|mw=no|m=no|species=no|voy=no|b=no}}

{{Optical illusions|state=collapsed}}
{{Douglas Hofstadter|state=collapsed}}

[[Category:Word play]]
[[Category:Constrained writing]]
[[Category:Rotational symmetry]]
[[Category:1983 neologisms]]