Great for Quilting, Sewing, scrapbooking and general crafts. Hot fix Glue is already on the back of the stones (Black color shown on the back of the stones in the image). Place the stones on the working material with glue side down. Use applicator tool or iron (without steam) directly on the crystal part of the stones. Glue melts when heat is applied through Hot fix Applicator Tool or Iron(without steam). Wait few seconds for the stone to get cold. Once set properly our stones are Completely Hand and Machine Washable. Size: 4mm Use: Iron on Decoration Included: 60 pieces per pack