A design that presents several instances of words when rotated through a fixed angle. This is usually 180 degrees, but rotational ambigrams of other angles exist, for example, 90 or 45 degrees. The word spelled out from the alternative direction(s) is often the same but maybe a different word to the initially presented form. A simple example is a lower-case abbreviation for “Down”, dn, which looks like the lower-case word up when rotated 180 degrees.
A design that can be read when reflected in a mirror, usually as the same word or phrase both ways. Ambigrams that form different words when viewed in the mirror are also known as glass door ambigrams because they can be printed on a glass door to be read differently when entering or exiting.
A design in which the spaces between the letters of one word form another word.
A version of space-filling ambigrams where the tiled word branches from itself and then shrinks in a self-similar manner, forming a fractal. See fractal of the word TREE as an animated example.
A design where an object is presented that will appear to read several letters or words when viewed from different angles.
A design with no symmetry but can be read as two different words depending on how the curves of the letters are interpreted.
A natural ambigram is a word that possesses one or more of the above symmetries when written in its natural state, requiring no typographic styling. For example, the words “dollop” and “suns” are natural rotational ambigrams. The word “bud” forms a natural mirror ambigram when reflected over a vertical axis. The words “CHOICE” and “OXIDE”, in all capitals, form a natural mirror ambigram when reflected over a horizontal axis. The word “TOOTH”, in all capitals, forms a natural mirror ambigram when its letters are piled vertically and reflected over a vertical axis.
This is an ambigram in Dan Brown’s mystery-thriller novel Angels and demons designed by John Langdon.
After this book’s publication, awareness on ambigrams has increased.
Such ambigrams that fuse two words within one set of curves are also known as Symbiotigrams.