A catch-all tag for either unfinished works in progress that lead to a final production work, or ancillary reference materials used in the production of a work. This is almost always official art, with the exception of production work of individual doujin animations.
- works drawn on animation paper to be used as with a peg bar, or featuring trim marks for later editing
- color traces
- partially colored art (when a reference or a piece of pre-production artwork)
- key frames
- animatics (very rough pre-production animations)
- photos or scans of physical cels used in a traditionally animated work
As well as production references such as: