3M sanding sponges are designed for sanding wood， paint， metal， plastic or drywall. This sponge features conventional 3M abrasives and is made with durable， flexible foam. 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.