Rotoshop is a proprietary graphics editing program created by Bob Sabiston.
[1] Rotoshop uses an animation technique called interpolated rotoscoping, which was used in Richard Linklater's films Waking Life and A Scanner Darkly, as well as the Talk to Chuck advertising campaign for Charles Schwab.
In order to manage different objects in the scene, the user can break the drawing into layers.
A layer can be "frozen" so that a single drawing remains visible throughout the entire scene.
This frees the user from having to repeatedly draw these elements for every frame in the sequence.