If you busy creating 3D digital models and don’t know about the Netherlands-based CG Textures database, it is worth the look. Run by a friend, Marcel Vijfwinkel, he generously has an open source attitude to the content. You can read the license here. A lot of the material comes from Marcel himself from his work in the gaming industry, and the site now has many content contributors. If you or your office are able to pay for a year-long membership, it will support the site and give you multiple perks.