1 When you have a blob of grape jelly or some other stain on your clothes, you try to get rid of it. But in the artistic world, there is one kind of stain that is beautiful. It comes in all colors of the rainbow. You would want to keep this kind of stain. It is called stained glass.
2 Stained glass looks vivid when sunlight shines through it, and it creates dots of color across the floor. You may have first seen stained glass in a church. No one knows who created stained glass for the first time, but early stained glass was created for Christian churches. Mosaics may have inspired this art form.
3 Glass artists of the Middle Ages developed the ability to make large pieces of colored glass. They first used a gold frame to hold pieces of glass together to use as a decoration. Then, these artists had a new idea. They decided to make a lead framework to hold these pieces of glass together. They thought this was a splendid way to create stunning new windows that was not as expensive.
4 Glass is a delicate and mysterious substance. It is fragile, but it is made from a coarse, natural material. It comes from sand! In ancient times, artists learned how to add metallic salts and oxides while they were making the glass to create vivid colors. Gold added to the glass made a cranberry color. Cobalt made blue. Silver made yellow and gold, while copper made green and deep red.