Does a tag exist for art which is drawn in the style that animators often draw key frames? I'm thinking posts like these:
post #910057 (here tagged key_frame, perhaps we could formalize this if such a tag does not exist already)
Many of the posts under production_art fall under this style; however, that tag refers to the source of the work as opposed to the actual aesthetic. I'm thinking sketch is too general, since it covers any kind of rough or unfinished looking piece in general.