Stained Glass Copper Foil Technique
Copper foil is a stained glass leading technique that has a more delicate or intricate look to it than the lead came technique. Louis C. Tiffany created the copper foil technique in the early 1900’s. Tiffany didn’t have the adhesive-backed copper foil that we have today. When he built his copper foil stained glass projects, he painstakingly cut the copper strips and applied wax to them to secure it to the stained glass.
Copper foil is often used for decorative glass boxes, stained glass lamps, and other stained glass projects with intricate curves. The copper foil is flexible and when the solder bead is applied correctly, it is strong enough for just about any stained glass project.
Deciding whether to use copper foil or lead came on a project is mostly a personal choice; yet, some areas may have building restrictions or codes that you might want to check. Some people believe that the copper foil method of stained glass construction is not strong enough for large stained glass windows.
There are methods of reinforcing stained glass windows whether they are constructed by the copper foil method or the came method. Rebar is used to reinforce large stained glass windows. There is a copper flat wire called “Strong Line” that is also used as reinforcement by placing it between the pieces of stained glass before soldering.
The copper color of Tiffany’s thin strips of copper for his stained glass window construction would have shown in, for instance, clear glass. Today’s copper foil comes in various backing colors like copper, black, silver and brass. This gives the stained glass artisan choices of backing that will show up less through clear glass; and for instance, if you use silver backing on white stained glass, there will not be a line of shadow on the white stained glass near the solder lines.
Also, if you plan to leave the solder lines silver and not use a patina to color the solder, then silver back will look better wherever there is clear glass. The same works for using a copper patina on the lead; you would want copper backed foil on your stained glass. Black-backed foil would look best on that clear glass if you are using black patina.
Copper foil tape is a “dead soft copper” which, when burnished onto the stained glass, sticks closely to the glass. It comes in various widths with popular sizes being: 1/8″, 3/16″, 1/4″, 7/32″ 3/8″ and 1/2″. Most copper foil tapes are in 36 yard rolls.
When working with larger stained glass projects, 3-dimensional articles or windows, a wider copper foil like 3/8″ or 1/2″ will be stronger. Thicker stained glass requires a wider tape. When you are doing very intricate or delicate stained glass work, you might prefer to use the narrower 3/16″ copper foil tape.
When you wrap stained glass in copper foil tape, be sure that the edges of the glass are ground and then cleaned very well; otherwise, the foil will not stick to the stained glass. Wrapping the glass edges carefully and being sure equal amounts of foil are folded up onto either side of the stained glass will ensure a smooth, even solder line. Be sure to rub or burnish the foil until it is smooth and secure.
Copper foil for stained glass construction is available through wholesale distributors all over the world. A very popular and reliable copper foil is manufactured by Edco Supply Corporation in Brooklyn, New York. Stained glass retail stores, craft stores, and online stores carry copper foil for stained glass.