Shading is a technique that artists and students use to capture gradation between light and dark. In this tutorial Shading Tutorial - Understanding the Art of Shading Rebekah Lynn tells us that her explanation is meant to teach shading techniques for realistic art. Other types of art may use different methods. The technique she explains is about subtle changes of tone and she shows how to capture this gradation in a step by step manner.
To begin with I suggest that you set out to teach the students about shading by concentrating on that one concept alone, rather than teach other complex aspects of drawing at the same time.
Here is a suggestion for an exercise that might be appropriate when you introduce the topic.
If you set this exercise up this way the students will be quite clear about the task at hand.
If you want to make sure they understand and can clearly place this within in their own goal setting framework, have them decide the criteria for assessment with you.
Like to talk about this exercise? Please post questions or comments on the discussion boards.
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