An ashcan copy is a term that originated in the Golden Age of Comic Books, meant to describe a publication produced solely for legal purposes (such as copyright), and not normally intended for distribution. "Publishers had to produce only two copies of each copyrighted "ashcan" production – 1) for the Library of Congress and 2) for their records – fewer than five copies exist for most of these productions."
During the golden age of comics, ashcan editions of comics were printed to establish copyright. They often went straight from the printer to the "ashcan". Today, "ashcans" could more accurately be described as mini or digest comics.
The word ashcan is a synonym for any type of waste receptacle whose contents are to be incinerated. The implication in comic publishing is that the printed material will go straight from the printer to the trash, which was often the case. Ashcan editions frequently contained unlettered stories and unfinished art. Their purpose was simply to justify the publisher's claim to a title, thereby preventing a competitor from publishing the same title or a similar one. Ashcans were also produced to demonstrate the publications to potential advertisers.
One example, called the "best known ashcan race", is Flash Comics #1 by Fawcett Comics, which introduced Captain Thunder (later Captain Marvel). Competitor All-American Comics had already published a Flash Comics title, and created a character named "Captain Thunder", so the Flash Comics ashcan failed to claim those trademarks for the company, but it did establish a publication date for copyright purposes.
Ashcan- A publisher's in-house facsimile of a proposed new title. Most ashcans have black and white covers stapled to an existing coverless comic on the inside; other ashcans are totally black and white. In modern parlance, it can also refer to promotional or sold comics, often smaller than standard comic size and usually in black and white, released by publishers to advertise the forthcoming arrival of a new title or story.
In modern comics, ashcan editions may refer to promotional comics in the independent/self-publishing market. The term is sometimes synonymous with minicomics or special variants.
The term has spread to other forms of media - for example, a film might be rushed into production on a low budget and shown in just one theater in order to maintain a company's copyright hold over a character or series (as was suitably the case with the 1994 film adaptation of the Fantastic Four).