Production Cel: A cel that was actually used to produce an animated cartoon or feature film. The outline of each image is created by either tracing the original animator's drawing or by photocopying it onto a sheet of clear celluloid. The cels are then painted on the reverse side to color the image.

Animation Drawing: These are the original drawings created by animators from which the production cels are traced or Xeroxed. While cels may be beautiful, some people say that the original drawings are the true animation art. The terms "clean-up" and "rough" refer to the line quality of the drawing. Animators usually work in roughs and leave the clean-ups to assistants. Clean-ups may be done directly over animators' roughs, either erasing or leaving the original lines, or they may be fresh drawings traced from roughs.