HTGSupply 100 Foot by 4 Foot Roll Heavy-Duty Reflective Diamond Foil on Black Poly Film, 6.7 Mil Premium diamond-textured liner ; highly-reflective silver Mylar on black poly Lightproof ; waterproof ; pressed diamond pattern reduces 'hot spots' and improves light distribution Heavy-duty 6.7-mil (.0067-inch) thickness Hangs easily using tape, staples, tacks, adhesive, etc. Roll measures 4' x 100'