Editing Traditional animation (section)

===Ink and paint===
Once the clean-ups and in-between drawings for a sequence are completed, they are prepared for a process known as ''ink and paint.'' Each drawing is transferred from paper to a thin, clear sheet of plastic called a ''[[cel]]'', a contraction of the material name [[celluloid]]. (The original flammable [[cellulose nitrate]] was later replaced with the more stable [[cellulose acetate]].) The outline of the drawing is inked or [[Xerography|photocopied]] onto the cel, and [[gouache]], [[acrylic paint|acrylic]] or a similar type of paint is used on the reverse sides of the cels to add colors in the appropriate shades. The transparent quality of the cel allows for each character or object in a frame to be animated on different cels, as the cel of one character can be seen underneath the cel of another; and the opaque background will be seen beneath all of the cels.

Disney experienced a setback to its ink-and-paint department due to [[World War&nbsp;II]]. When peacetime resumed, much of the original equipment went to waste as more economic solutions were sought, leading to the [[#Xerography|xerography]] process pioneered by [[Ub Iwerks]].{{sfn|Thomas|Johnston|1995|pp=280-281}}