Sandpaper - Wikipedia
It is common to use the name of the abrasive when describing the paper, e.g. "aluminium oxide paper", or "silicon carbide paper". The grit size of sandpaper is usually stated as a nuer that is inversely related to the particle size. A small nuer such as 20 or 40 indies a coarse grit, while a large nuer such as 1500 indies a fine grit.