In typography, a length of typeset material output for proofing. The term derives from the days of hot metal, where a galley was a metal tray with raised edges that held about 20 inches of metal type, which was then proofed and handled. Galley thus came to refer both to the amount of material and its state. Since a galley proof was made right after type was set, it was a first, or reading, proof. Subsequently, the material would be corrected and organized into pages, creating final page or repro proofs, made up with elements in position. Thus, a galley is a rough proof or copy of a length of typeset material.
Today, galleys are not usually of equal lengths, although systems can be programmed to make them so. In book publishing, there are several types of galleys, commonly considered as "first-pass pages," which are the first typeset pages of a book, and "second-pass pages," which are revised and corrected proofs and are commonly close to the final pagination of the book. "Bound galleys" are first-pass proofs cut into pages, bound with a cover, and sent out to early reviewers or used for promotional material. In electronic publishing systems, sheets of type, not yet assembled into final pages, output to a laser printer are often referred to as galley's.