This Pro Grade Sandpaper Has A No-Slip Backing That Won'T Slip Or Slide During Use. Reduced Hand Fatigue. The Sandpaper Is Clog Resistant. The Purple Abrasive Will Not Discolor The Surface You Are Sanding. No-Slip Grip Backing Provides Longer Sheet Life 7-Times Longer Than Conventional Sandpaper. For The Best Sanding Results, Sand With The Grain Of The Wood And Work Through A Sequence Of Grits, From Coarse To Ultra Fine, Skipping No More Than One Grit Between Sandpaper.