On the history and creation of ambigrams, by a pioneer of the practice“Spellbinding and truly one-of-a-kind. These doubly readable words and phrases, if designed by an artistic eye and hand, could possess great visual beauty. Douglas Hofstadter named such calligraphic creations “ambigrams,” and over the decades he has designed thousands of them, as have his friends Scott Kim and John Langdon, the other main pioneers of the subtle art form he calls ambigrammia. ABCD (Hofstadter’s informal title for this book) offers a sampler of hundreds of Hofstadter’s ambigrams, along with a few dozen by Kim, Langdon, and others. With deep links to cognitive science, ABCD exhibits ambigrams of many types and shows how ambigrammia can be extended in surprising directions.