Sandpaper is produced in different sizes and is used to remove unwanted material from surfaces, either to make them smoother (in painting and wood finishing), to remove a layer of material (e.g. old paint), or to make surface rougher (in gluing).
Types
Backing: Backing for sandpaper can have clothes (cotton, polyester, and rayon), PET film, and "fibre", or rubber apart from the paper.
Material: Garnet, emery, aluminium oxide, silicon carbide, alumina-zirconia, Chromium(III) oxide, ceramic aluminium oxide can also be used in sandpapers.
Bonds: Different adhesives, such as Hide glue, are used to bond the abrasive to the paper. Waterproof sandpapers use resin bond and a waterproof backing.
Open coat sandpapers have particles that are separated from each other and it is more flexible.