A broadside (broadsheet) is a sheet of paper printed on one side only. Almanacs, indulgences, advertisements, bulls (proclamations) and so on were printed in the form of broadsides. Gutenberg and Fust, as well as Caxton, printed indulgences. Broadsides carrying advertisements of printed books or type specimens were also produced. A catalog of broadside incunabula was published under the title Einblattdrucke des XV. Jahrhunderts, in 1914, slightly earlier than the comprehensive union catalog of incunabula GW (1925-).