Illegal stag films or blue films as they were called, were produced underground by amateurs for many years starting in the 1940s. Processing the film took considerable time and resources, with people using their bathtubs to wash the film when processing facilities (often tied to organized crime) were unavailable. The films were then circulated privately or by traveling salesman but being caught viewing or possessing them put one at the risk of prison.
In the 1940s, the word "pinup" was coined to describe pictures torn from men's magazines and calendars and "pinned up" on the wall by U.S. soldiers in World War II. While the '40s images focused mostly on legs, by the '50s, the emphasis shifted to breasts. Betty Grable and Marilyn Monroe were two of the most popular pinup models. In the second half of the 20th century, pornography evolved into the men's magazines such as Playboy and Modern Man of the 1950s. In fact, the beginning of the modern men's glossy magazine (or girlie magazine) can be traced to the 1953 purchase by Hugh Hefner of a photograph of Marilyn Monroe to use as the centerfold of his new magazine Playboy. Soon, this type of magazine was the primary medium in which pornography was consumed.