The copper foil technique unlike the leaded technique requires more elbow grease, for it is more labor intensive. The process of foil begins with the cutting of each piece of glass, then ground for an exact fit. Each individual piece is wrapped in copper foil tape on its edges. The copper foil is firmly pressed down over the edge and face of the glass. Once all the pieces have been wrapped and laid out properly on the design pattern, the window is soldered front and back. You can choose to patina the solder black or copper tone.