Slide 23 & 24 of 52

In traditional computer graphics, we shade an object by adding white, in the case of highlights, or black, in the case of diffuse shading, to the hue or color of the object. Adding white or black to a given color results in what artists call tints in the case of white, and shades in the case of black.

Artists, however, use an additional technique which involves adding gray to the hue of an object, resulting in colors know as tones.

Tones are considered a crucial concept to illustrators and are especially useful when the illustrator is restricted to a small luminance range.