sandpaper

Strong paper coated with (traditionally) sand or (today) manufactured aluminum oxide, silicon carbide, or other abrasive material, used for smoothing and polishing.

Near-synonym: emery paper

They like to finish it off with a piece of 600-grit sandpaper before cleaning and painting.

A sheet of such paper.

I need a scraper and a sandpaper over here.

To polish or grind (a surface) with or as if with sandpaper.