If the animation is successfully pencil tested and approved by the director, clean versions of the drawings have to be done.
The artist doing the clean-ups is responsible for the final line and finished look of the drawn character or object.
Clean-up animation is the process of creating the final drawings you see in the finished film.
The clean-up artists will follow the intentions of the animators and stay true to performance and movement.
On average, clean-up usually takes twice as long as the rough animation because of the precision and extra drawings that are required to complete a shot.