Signature (print)

In print production, a signature is a single sheet of paper folded multiple times to create a specific number of pages. When signatures are stacked in sequence and bound together, they form the text block of a book or booklet. The number of pages in a signature is always a multiple of four, as each physical sheet contributes four printed surfaces.

Signatures are the fundamental building blocks of perfect-bound and case-bound volumes. Printers typically print large sheets that are then folded into signatures of eight, sixteen, or thirty-two pages. This method allows for efficient printing and consistent page alignment. Understanding signature structure is critical for designers, as it dictates where page breaks occur and influences the imposition layout to ensure pages appear in the correct order after folding.