Actually, I suspect that the problem is not the thumbnail at all... and that there might not really be a problem. A texture map should be applied to a plain white model if all you want to show is the texture. You can "tint" the texture by painting the undermodel, and the resultant render will be a blend of colors. Many people go through their models and whitewash them if they intend to use elaborate texture maps (be sure to keep your originals safely somewhere). There is a python script to automate this in ProPack. Many modelers release the object in question as a white model, especially if they supply more than one texture map for it, and thus you'll get a white image in the thumbnail box. Carolly