3M 17091CLR Command Strips let you hang items on walls damage-free. They're perfect for smooth surfaces like painted walls, metal, glass, and finished wood. To apply, clean the surface with rubbing alcohol, separate the strips, remove the black liner and apply the strip, press firmly for 30 seconds, remove the blue liner and apply the hook, press firmly for 30 seconds. To remove, stretch the strip straight down along the wall at least 12 inches until it releases.