Tijuana bibles (also known as eight-pagers, Tillie-and-Mac books, Jiggs-and-Maggie books, Jo-Jo books, bluesies, blue-bibles, gray-backs, and two-by-fours) were palm-sized erotic comics produced in the United States from the 1920s to the early 1960s. Their popularity peaked during the Great Depression era. (source: Wikipedia)
