Whether you want to create a gallery wall or install the family chore chart, this pack of 16 3M Scotch(R) double-coated mounting squares deliver a strong and permanent bond on contact in only 30 minutes, without requiring the use of a hammer or nails. A piece of 40" (101.6 cm) can hold up to 10 lb (4.5 kg), which means approximately 1 lb per 4" (0.45 kg per 10.2 cm) of tape. Perfect for use on finished or painted surfaces, metal, tile and more, these squares are intended for indoor use only. For an optimal bond, make sure your surface is smooth, clean and dry. These white tapes have a length and width of 1" (2.54 cm).