4 Grades of Sandpaper: Easily identify the different grades based off corner markings! Customers will receive all 4 grades of sandpaper with their order. 120, 220, 320, and 400-grade sandpaper! The different grades help with a variety of projects including Nantucket Basketry. This sandpaper is designed for hand sanding your mold, base, rim, or any wooden basket supplies.