Positive and negative relief
From Infogalactic: the planetary knowledge core
Lua error in package.lua at line 80: module 'strict' not found. Positive and negative relief is an art technique that are usually done over graph paper to show a pattern will "pop" up in the page. Sometimes it is considered as an optical trick. [1]
The technique is done by alternating two contrasting colors, such as black and white, on the grids. A pattern is then drawn over the grids, and the parts of the pattern in the grid will be coloured by the opposite colour that the grid inherits.
