From Fan History Wiki
Tijuana Bibles were pornographic comic books produced from the 1920s to the 1960s. Typically 4x6 inches and size and 8-12 pages long, these crudely-printed underground comics by generally unknown artists and writers were at their most popular during the Great Depression.
What is particularly of note from a fandom perspective is that many of these books featured well-known celebrities of the time, such as Clark Gable, Mae West, and even Al Capone. They also featured popular comics characters and characters from Disney features such as Snow White, making Tijuana Bibles an early form of adult "fan-fiction" and RPF.
It is known that Tijuana Bibles first began appearing in the United States in the 1920s, although the exact publishing dates of these are unclear. It is believed they probably originated from the large newsprint presses in Brooklyn or Newark, being published discreetly after-hours. Distribution was, however, highly organized (perhaps by organized crime organizations) and copies began appeared in numerous cities.
The 1930s, being the "Golden Age" of comics, with such characters as Buck Rogers, Flash Gordon, and Dick Tracy all appearing in full-length comic books and movie serials--and sometimes those same characters now appearing unofficially in Tijuana Bibles as well. Printing became better quality, as did the artwork, although the subject matter remained as crude and pornographic as ever. "Mae West & Popeye" is one of the few accurately dated books, showing it was first published in 1935.
In the 1940s the paper shortage caused by World War II made it more difficult to print Tijuana Bibles, so any old scraps of papers were utilized including old technical documents, shipping tage, and obsolete books. After the war, the Tijuana Bibles began to decline in popularity as mainstream "girly mags" became more and more explicit in content. Mainstream comics in the 1950s were also becoming more graphic in their depictions of sex and violence, and production of Tijuana Bibles slowed more to only local, underground distribution.
The counterculture movement of the 1960s meant some continued popularity for Tijuana Bibles, including a series produced featuring the erotic adventures of Snow White and her seven dwarfs. The 1970s saw the reprinting of some classic bibles by underground comic press, but few new titles. No longer profitable, only the occasional title would appear into the 1980s, although the subjects remained as topical as ever: Ronald Regan, Star Wars, Pee Wee Herman...
In Alan Moore's graphic novel Watchmen, first published in 1986, there is a scene in which Sally Jupiter, the first Silk Spectre, proudly shows her daughter Laurie Juspeczyk a Tijuana Bible sent to her by a fan portraying her in erotic adventures. Laurie reacts in horror to the idea while her mother finds it a complement that she had been the subject of such work.
The website Tijuana Bibles features a number of scans of complete issues.
- Bob Adelman, Tijuana Bibles : Art and Wit in America's Forbidden Funnies, 1930s-1950s, New York: Simon & Schuster, 1997, ISBN 0-684-83461-8
- Susie Bright; "Dogeared Style," Salon.com 
- Art Spiegelman; "Those Dirty Little Comics," Salon.com 
- Michael J. Weller; "The Secret Blue Book", Home'Baked Books, 2005, London