I bought this book because I want to improve my drawing skills. Even in these initial stages of using it, Lee Hammond's comments on the 5 elements of shading have made an enormous difference. Significantly, Lee says in her analysis of tonal values in drawings that "The most famous phrase I use in my classes is "Get it darker!" Not going dark enough will cause your drawing to lack depth." This comment has given me the confidence to 'go darker' myself - with the effect of making some of my pictures really live, through greatly improved light and dark contrasts.