Light and Shade
Shade with the idea that light and shade are to aid the outline you have drawn in giving the impression of solidity, breadth and depth. Keep before you the conception of a solid body of four sides composed of a few great masses, and avoid all elaborate and unnecessary tones which take away from the thought that the masses or planes on the sides must appear to be on the sides while those on the front must appear to be on the front of the body. No two tones of equal size or intensity should appear directly above one another or side by side; their arrangement should be shifting and alternate.
There should be a decided difference between the tones. The number of tones should be as few as possible. Avoid all elaborate or unnecessary tones and do not make four tones or values where only three are needed. It is important to keep in mind the big, simple masses and to keep your shading simple, for shading does not make a drawing.
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