Light and shadow define form and give weight to drawings. For this exercise use a middle tone paper, blue or grey pastel paper, brown wrapping paper or grocery bags will work. Draw objects that are not colored or pattered and are set up in strong directional light. Light colored objects will have the most distinct shadows. Draw the shadows with black and the reflected light with white. Leave the middle tones open for the middle tone paper to show through. Shadows and reflected light define form and give the subject weight.