Creating Organic Materials - Blender Cycles Materials and Textures - page 335

F From step 9 to 15, we built the basic shader for the alien Suzanne's skin; the
diffuse component is mixed and modulated by the Fresnel output, with a specular
component made by two summed Glossy BSDF nodes with different roughness
values, so as to have a crisper specular effect on a more diffuse one, and with
the additional help of the SSS_group node to simulate a reddish Subsurface
Scattering effect.
F From step 16 to 33, we built the quite complex bump pattern for the skin by mixing
the outputs of three different types of procedural textures with the help of both the
Math and MixRGB nodes, and the variations provided by the ColorRamp nodes.
F Finally, from step 34 to 41, a simple grayish color pattern is modulated through the
Dirty Vertex Colors layer data that comes from the mesh and that uses the first part
of the bump pattern to add variation.