Screen-Bak inter-woven polyester knit backing with abrasive grain on both sides. Open mesh for load resistance. Rinse and reuse for longer sanding life. Tends to cut more aggressively than paper or cloth. Also available silicon carbide. Use for removing old finishes and wax, final sanding stages to remove raised wood fibers, and in between coats to scuff the surface. Use drive pad assembly & synthetic flood pad w/screen.