Public domain comics are comics that are no longer protected by copyright law. This usually is because the legal procedure required to maintain copyright protection was not followed, allowing the copyright on the material to lapse. This often happens because the publisher has ceased operations by the time the copyright is due for renewal. The artist and writer, meanwhile, have no legal standing to renew the copyright because the comic was a work made for hire. Many publications from the 1930s and 1940s, which is considered the Golden Age of Comics, have become public domain comics.
Copyright law is designed to protect the creators of public works, allowing them to decide how their works are used or displayed and to receive payment when such usage happens. The United States and most other nations have their own copyright laws, and further protection is afforded by the international agreement called the Berne Convention. Works created in the U.S. from the 1920s to the 1960s required registration and renewal to enjoy this protection. If these requirements were not met, the copyright protection lapsed, and the work effectively became public property. The legal term for this status is "public domain."
Early comics creators and publishers generally had no idea they were creating a lasting art form. In the 1930s and '40s, comics were often considered disposable entertainment for children. This opinion persisted among artists and publishers of comics as well as the general public. Comic magazines were often produced and published cheaply, and were not expected to have any value after their sale at the newsstand. This sort of thinking led to many of these publications later becoming public domain comics.
In those early days, comics magazines enjoyed sales in the millions, figures they would not see again until the 1990s. Many artists saw comics as a necessary chore to pay the bills until more prestigious work was available; they often used pseudonyms. Meanwhile, publishers printed comics to reap the benefits of the sales boom. When it faded in the 1950s, many of them abandoned comics for more successful ventures in or away from the publishing industry. Few cared enough to renew the copyrights on these books, allowing them to become public domain comics instead.
Until the 1990s, it was standard practice in the comics industry for artists to sign “work made for hire” contracts. This meant that they relinquished all legal rights on the work to the publisher. So even if they had an interest in securing copyright to their work, few artists had the legal or financial resources to do so. Early stories featuring characters such as Captain Marvel, Sheena the Jungle Queen and Phantom Lady have become public domain comics. These characters have since been revived by other publishers; some of the original comics are available for free downloading on the Internet.