The following are shading techniuqes except?

Bleaching lightens materials, not drawings. Shading creates dark and light areas in artwork. These are different processes.

Hatching, cross-hatching, and blurring all create shading. They use lines or smudging to show tone. Bleaching is not a drawing technique.

Shading gives drawings depth and form. Different techniques create different effects. Artists choose methods based on desired results.