Cel shading or toon shading is a type of non-photorealistic rendering designed to make 3D computer graphics appear to be flat by using less shading color instead of a shade gradient or tints and shades. A cel shader is often used to mimic the style of a comic book or cartoon and/or give the render a characteristic paper-like texture. There are similar techniques that can make an image look like a sketch, an oil painting or an ink painting. The name comes from cels, clear sheets of acetate which are painted on for use in traditional 2D animation.