TicTacToon provides a set of tools to support sketching, flipping
among sketches and turning the viewpoint.
Sketching: Animators begin drawing in-betweens by stacking the
initial and final key drawings. They put a new sheet of paper on the
lightbox, turn it on, and sketch an in-between, according to the keyframe animator’s instructions. They regularly check their drawings
by turning off the light. The in-between animator must sometimes
superimpose different parts of key drawings. For example, if a character jumps and his arm also moves, the movement of the arm may
be seen more easily by superimposing the arms of the two key drawings