Free–Form Strokes
When drawing, in traditional animation, the most striking
characteristic is the freedom the animator has. He can easily
draw all kinds of stylish curves on paper just by using one
pencil, he dynamically can alter the width and the curvature
of the curves and moreover, when the animator is not satisfied
with the result, he can make (simple) corrections just by
drawing new curves along or on top of the “wrong” ones.