These abrasive sheets are the choice of professional woodworkers for sanding a wide variety of bare and unfinished goods. Manufactured from a unique Aluminum Oxide, which fractures into new, sharp edges as it wears.320 Grit Premium Woodworking Sandpaper 4-1/2" x 11" Sheet (40 Sheets), 40PK This material is an excellent substitute for garnet paper, and in most applications will outlast garnet..