Squash and stretch also defines the rigidity of the material making up an
object. When an object is squashed flat and stretches out drastically, it
gives the sense that the object is made out of a soft, pliable material and
vice versa. When the parts of an object are of different materials, they
should respond differently: flexible parts should squash more and rigid parts
less.
An object need not deform in order to squash and stretch. For instance, a
hinged object like Luxo Jr. (from the film, Lv, xo Jr. I21]), squashes by
folding over on itself, and stretches by extending out fully. (figure 3)