I have a scene where all of the objects have a material assigned to them. However, it would be useful if I could temporarily assign them a special material which simply a texture map of a grid square. The point of this would be to let me see the UV lines to help me make editing decisions.
As far as I can tell, Blender does not allow you to do this. Am I wrong? Is there some way to temporarily view my scene with this grid material and then switch back to the materials I've assigned?