Tijuana bibles (also known as eight-pagers, Tillie-and-Mac books, Jiggs-and-Maggie books, jo-jo books, bluesies, gray-backs, and two-by-fours) were palm-sized pornographic comic books produced in the United States from the 1920s to the early 1960s. Their popularity peaked during the Great Depression era.
Most Tijuana bibles were obscene parodies of popular newspaper comic strips of the day, such as "Blondie", "Barney Google", "Moon Mullins", "Popeye", "Tillie the Toiler", "Dick Tracy", "Little Orphan Annie", and "Bringing Up Father". Others made use of characters based on popular movie stars and sports stars of the day, such as Mae West and Joe Louis, sometimes with names thinly changed. Before the war, almost all the stories were humorous and frequently were cartoon versions of well-known dirty jokes that had been making the rounds for decades.
The artists, writers, and publishers of these booklets are generally unknown, as their publication was illegal, clandestine, and anonymous. The quality of the artwork varied widely. The subjects are explicit sexual escapades usually featuring well-known newspaper comic strip characters, movie stars, and (rarely) political figures, invariably used without respect for either copyright or libel law and without permission. Tijuana bibles repeated the ethnic stereotypes found in popular culture at the time, although one Tijuana bible ("You Nazi Man") concluded on a serious note with a brief message from the publisher pleading for greater tolerance in Germany for the Jews.
The typical "bible" was an eight-panel comic strip in a wallet-sized 2.5 × 4 inch format (approximately 7 × 10.5 cm) with black print on cheap white paper and running eight pages in length.
Tillie and Mac are thought to have been the first Tijuana bible stars, along with Maggie and Jiggs from the popular newspaper strip Bringing Up Father. Tillie was soon followed by Winnie Winkle, Dumb Dora, Dixie Dugan, Fritzi Ritz, Ella Cinders, and other familiar comic strip characters stamped in the same mold. Popeye and Blondie were the most popular cartoon characters appearing in Tijuana bibles in the 1930s, judging by the number of their appearances. The first celebrity bibles were based on real-life newspaper tabloid sex scandals such as the Peaches and Daddy Browning case which made headlines in 1926. Ten years later, an entire series of bibles by one unknown artist obscenely lampooned Mrs. Wallis Simpson and the King of England. By far the most popular celebrity character was Mae West, but virtually every major Hollywood star of the era was featured in the Tijuana bibles, obscenely and libelously.