Sandpaper, real name glasspaper, is a heavy paper with abrasive material attached to its surface. Sandpaper is part of the “coated abrasives” family of abrasive products. It is used to remove small amounts of material from surfaces, either to make them smoother, to remove a layer of material (e.g. old paint), or sometimes to make the surface rougher (e.g. as a preparation to gluing).