The art and science of glass making has been around for more than 5,000 years, and the use of stained glass dates back to the third or fourth century A.D. The 12^th century saw the most use of stained glass because of the rise of Gothic cathedrals.

Today, only about 10% of the stained glass in use is in churches. The rest is used in business and home applications. Most of the time, stained glass is used in windows, but it is now being used in lamp shades, ornaments, and in many hobby uses.

Stained glass begins in the same way any kind of glass does. Silica, potash or soda, and lime or lead oxide are fused together. To make stained glass, some kind of metallic oxide is added to these materials.

Copper oxide can add ruby, blue, or green colors depending on conditions. Cobalt produces most shades of blue. Chromium and iron oxide are used to make green shades. Uranium, titanium, or cadmium sulfide can produce gold colors.

The method for making stained glass is the same now as it was in the Middle Ages. The glass in leaded glass windows is made by first catching up a lump of molten glass at the end of a blow pipe. It is then blown out into a cylinder, cut off the blow pipe, flattened, and cooled.

One of the variations of this process, called flash glass, is made by dipping the lump of molten white glass into molten colored glass. When this is blown, cut, and flattened, it produces stained glass with a less intense color due to the white backing.

Another kind of glass that can be used in stained glass is called “Norman slabs.” In making this kind of glass, the molten glass is blown into the shape of a four-sided bottle. The sides are then cut into slabs that are thin at the edges and may be a quarter inch thick in the middle.

Cathedral glass is rolled out into flat sheets that are very regular in texture and thickness. Marine antique glass is similar but has a more bubbly texture.

All of these kinds of stained glass can be used to make beautiful windows or other things that are both good at letting in light and in evoking emotions through the stories they can tell.

When you consider decorating with stained glass, you may need someone who can make some suggestions. Whatever kind of glass you have when you need repair or replacement, call FEDERAL GLASS AND MIRROR at 508-872-3563. Mike and John Purpura have a long family history of excellence in many types of glass replacement and installation.