1/2" Wide Copper foil tape has an acrylic adhesive backing designed to withstand the heat of soldering.  The copper foil tape is used as the base for your soldering.  The width is perfect for wrapping 4 pieces of our 1mm thick glass together with art sandwiched between, with room to trim any un-even edges. Lisa uses this width to wrap thicker glass or other thick objects like beads, cabochons, or any other shaped object.9 feet will go a long way for small projects!