An ashcan comic is a form of the American comic book originally created solely to establish trademarks on potential titles and not intended for sale. The practice was common in the 1930s and 1940s when the comic book industry was in its infancy, but was phased out after updates to US trademark law. The term was revived in the 1980s by Bob Burden, who applied it to prototypes of his self-published comic book. Since the 1990s, the term has been used to describe promotional materials produced in large print runs and made available for mass consumption. In the film and television industries, the term "ashcan copy" has been adopted for low-grade material created to preserve a claim to licensed property rights.