Methods for 2D nimation have been documented for a long time. Since the formation of the Disney Studios, their vast commercial output meant they had to find ways of passing on thrir skills to a large body of workers who needed to know the house style. The top animators started ti look at what they were doing as animators, and started to identify rules and guiding principles by which they worked. Most of these principles apply to model or puppet animation as well as – as thry are derived from the scientific study of movement – the effect of dravity, friction and force on masses. One of the greatest books to read about the developmet of 2D animation is Ollie Johnston and Frank Thomas’s the Illusion of Life