Sketchup Vray Material Library Free Download ^new^
This is a massive community-driven portal highly popular among architectural visualizers.
These are raw image files (Diffuse, Roughness, Glossiness, Bump/Normal, Displacement). You download these from sites like Poly Haven and manually plug them into a standard VRay Material slot. How to Install and Import .vrmat Libraries into SketchUp Sketchup Vray Material Library Free Download
A dedicated section for seamless architectural textures. This is a massive community-driven portal highly popular
3D-Wolf is a professional material creator. They offer a "Free Sample Pack" containing 15-20 photorealistic V-Ray materials. Sketchup Vray Material Library Free Download
Click the (Create a section / Add custom folder) at the bottom left.