5/16" Wide Wavy 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 5/16" Wavy tape gives a decorative border one side and a straight border on the other. The solder will only go where the foil is the result is a wavy soldered edge. It is perfect for wrapping 2 pieces of our 1mm thick glass with art sandwiched between, with room to trim any un-even edges. 9 feet will go a long way for small projects!