Gator Grit 25 Count 9" x 11" 80 Grit Medium General Purpose Sandpaper. The 80 grit medium sandpapers are designed for use on wood, metal, drywall, fiberglass and painted surfaces. You can use these sheets to sand by hand or with a machine. The sheets can also be used with an orbital sander by cutting the sheets into 1/2 sheet, 1/3 sheet or 1/4 sheet to fit your orbital sander.