The book contains several ambigrams created by real-life typographer John Langdon. Besides the "Angels And Demons" and "Illuminati" designs, the title of the book is also presented as an ambigram on the hardcover book jacket (see illustration at right on this page), and on the inside cover of the paperback versions. The book also contains ambigrams of the words Earth, Air, Fire, and Water, which has served to bring the art of ambigrams to public attention by virtue of the popularity of the book. The "Illuminati Diamond" mentioned in the book is an ambigram of the four elements arranged in the shape of a diamond.