cel animation

In order to save time and money Winsor McCay invented the animation cel in 1915. Instead of drawing on a single sheet of paper, and then redrawing the entire scene for every frame (12 for every second), the scene was drawn in parts, on a thin, transparent celluloid acetate or "cel". For example, the background would be drawn on the first layer, then the body of a character would be drawn on the next layer, then the head on the next layer and the expresion on the next layer. This made it easy to change an expression without having to redraw everything.

In order to make cel animation work correctly, everything has to be "registered". This means that both edges of every cel need to be punched with holes and placed over pins or pegs so that each cel lines up perfectly with the cel underneath it.

McCay first used cel animation to create the 25 minute flim The Sinking of the Luisitania which used over 25,000 drawings. Cel animation was also used by Walt Disney in all of his animated films including Snow White and The Seven Dwarfs. Cel animation continues to be the technique used by most quality animators.