Introduction
The purpose of this exercise is to develop facility at perceiving objects as physical shapes rather than as verbal descriptions. This exercise makes us "see" an object in an unusual way, and can help us draw what's actually there, rather than what we think "ought" to be there.
Description of the exercise
Find a simple object that isn't completely solid, such as a stool, a Windsor chair, a half-open pair of scissors, etc. With this object in front of you, draw the "holes," not the object (draw the outlines of the spaces where the object is not, instead of drawing the object itself). Each drawing should mostly fill a piece of 8.5" x 11" or larger paper.