This effect is actually pretty complex in real life. There are tiny strands there, which reflect and refract lights. Some patches are brighter, and some patches are darker, because the strands are facing different directions. It could be probably "faked" by using a contrasty normal map, but it would not recreate the complex effects like refraction, sss, etc. I will try returning here with some ideas, but maybe in the meantime other users will have some feedback.
I also remember similar topics in the 3ds Max section, so it may be worth searching for that.