Editing Imposition (section)

== Non-digital techniques ==
Imposition has been a requirement since the earliest days of printing. When pages were set using [[movable type]], pages were assembled in a metal frame called a ''chase'', and locked into place using wedges called ''quoins''.

By the late twentieth century, most typesetting was onto photographic film. These sheets were combined manually on a [[light table]], in a process called ''stripping''. Skilled workers would spend many hours ''stripping'' pieces of film together in the correct sequence and orientation. The term stripping was also used for other changes to a prepared page, such as a spelling correction, or a ''[[stop press]]'' story in a newspaper. Digital techniques rendered stripping less necessary, but what has forced increasing numbers to abandon it completely is the introduction of "platesetters", which put pages directly onto printing plates; these plates cannot be adjusted with a sharp knife. In addition, an extremely high precision would be needed for stripping of colour work, as each ink colour is on a separate piece of film.