This is a free Anisotropic Shading guide to help Blender users when designing their 3D models, extract from the free PDF guide and YouTube tutorial below, hope you find it useful :D :
Principled BSDF — Blender Manual
What does the anisotropic option do? - Blender Quick Tips #5 - YouTube
Anisotropic textures from Substance Painter to Blender : r/blenderhelp