In SketchUp, go to Extensions → V-Ray → Asset Editor .
Bookmark this page and revisit the sources every month. Designers frequently release free "holiday sample packs" (e.g., 50 free wood materials for Christmas). Happy rendering sketchup vray material library free download
The official V-Ray Material Library (accessed via the V-Ray Asset Editor) is extensive, but it requires a paid license. For students, hobbyists, or professionals on a tight budget, the search for a is a common but risky quest. In SketchUp, go to Extensions → V-Ray → Asset Editor