Use 3M Pro-Pak Sanding Sponges for sanding paint, wood, metal and drywall. This sponge features tough and durable aluminum oxide mineral. The block shape makes it easy to hold and sands flat, contoured, or irregular surfaces. Sanding is an integral step in preparing a surface to receive a coating. For the best sanding results, sand with the grain of the surface and work through a sequence of grits, from coarse to very fine, skipping no more than one grit between each sanding step.