Using these sanding sheets is a breeze. First, attach the sheet to your hook - and - loop sander. Then, gently move the sander over the surface you want to sand. For different materials and levels of smoothness, pick the appropriate grade. The 40 - grade is good for rough sanding, while the 240 - grade is great for fine finishing. When you're done, store the sheets in a dry place to prevent them from getting wet. If they get clogged with dust, you can tap them gently to remove the debris. And always wear safety goggles and a dust mask to protect yourself while sanding.