Forme (printing)

In typesetting, a forme (or form) is imposed by a stoneman working on a flat imposition stone when they assemble the loose components of a page (or number of simultaneously printed pages) into a locked arrangement, inside a chase, ready for printing. If metal type is kept locked up in the typeset document for long periods to allow reprint, this is called "standing type". There are many types of formes in printing in general.

The design of the printing surface and the material of the forme depend on the printing process employed. For instance, in letterpress printing, the forme is composed of type or stereotypes made from various materials. In intaglio printing, etched or engraved metallic cylinders are used, while offset printing employs chemically treated metal plates. In screen printing, the forme consists of a mesh with non-printing areas made impermeable to ink. In flexography, printing is done using either a directly engraved rubber cylinder or a digitally imaged photopolymer plate mounted onto a cylinder.

Some printing processes, known as NIP processes, operate without a physical forme.