4 Comparative Thinking Fitting the subject onto the drawing sur- face so that it fills the area intended for it, no more and no less, can be challenging. In fact, many an eraser has been worn down trying to achieve a nice fit. Yet with a little pre-plan- ning and some size comparisons, you can Have you ever concentrated so hard on getting a challenging part of your drawing completed that you forgot to keep track of the overall pic- ture and ran out of room? Did you end up sac- rificing the top of the subject's head or cutting off part of his legs to make him fit? Did your