3M Drywall Sheets are designed for sanding drywall joints, patching compounds and plaster. Made with sharp synthetic mineral for long-lasting performance. Pre-cut 4-3/16 in x 11-1/4 in and die-cut to fit most drywall sanding tools.The 3M Paper Drywall Sheets are designed for sanding drywall joint compounds (light or regular), patching compounds, and plaster. They are made with aluminum oxide, a tough synthetic mineral that cuts cleanly and leaves a smooth finish. The grit is 150.