Slide 19 & 20 of 52

One of the solutions to this dilemma is a strategy which Edward Tufte devoted an entire chapter to in his latest book, "Visual Explanations".

He has a case study of improving a computer graphics animation by lowering the contrast of shading and adding black lines to indicate direction.

In order to include shading in an image with edge lines and highlights, we need to use a compressed dynamic range for shading as well as using colors visually distinct from black and white.