Editing Traditional animation (section)

====Cel overlay====
A ''cel overlay'' is a cel with inanimate objects used to give the impression of a foreground when laid on top of a ready frame.{{sfn|Laybourne|1998|p=168}} This creates the illusion of depth, but not as much as a multiplane camera would. A special version of cel overlay is called ''line overlay'', made to complete the background instead of making the foreground, and was invented to deal with the sketchy appearance of xeroxed drawings. The background was first painted as shapes and figures in flat colors, containing rather few details. Next, a cel with detailed black lines was laid directly over it, each line is drawn to add more information to the underlying shape or figure and give the background the complexity it needed. In this way, the visual style of the background will match that of the xeroxed character cels. As the xerographic process evolved, line overlay was left behind.