It is sometimes referred to as cathedral glass, however it has nothing to do with medieval cathedrals, where the glass was hand-blown. The word "cathedral" comes from the Latin word for "grand church," and refers to any large church building with stained glass windows.
Church windows were originally made of clear glass but over time artists developed ways to color the glass. They would first make a template of what they wanted the window to look like in wood or cardboard and then have that pattern cut into thin strips of colored glass. These pieces were then placed in a mold behind the glass and heat was applied until they became hard like stone. The artists had great freedom in choosing colors for the glass; red, blue, green, and yellow were the only real options in 14th century Europe. By the 17th century scientists learned how to make other colors, including purple and orange.
The art of making colored glass reached its highest point around 1450-1550 in Europe. Glass makers in England and Germany were especially talented at coloring glass, using many different methods to create thousands of colors that we see today in old buildings.
After this point, the invention of the chemical light bulb in 1879 by Thomas Edison helped fuel the decline of the stained glass industry.
Cathedral glass is the trade term for monochromatic sheet glass. The phrase "cathedral glass" is often incorrectly attributed to cathedral windows as a substitute to the word "stained glass." Stained glass is both a material and an art form that involves the creation of colored windows with intricate or graphic designs. Cathedral glass can be used to create artistic effects without being considered stained glass.
There are several types of glass used in churches. Ordinary clear glass is used for ordinary windowpanes, while stained glass uses different colors of glass fused together into panes designed to look like flowers, stars, or other shapes. Transparent glass may be used in place of windowpanes. Church windows serve three main purposes: they allow light to enter the building during daytime hours, they offer views of the outside world to those inside the church, and they provide decoration for the room. Windows are made from glass plates or sheets which are cut and shaped by hand or using mechanical processes. In churches where money is no object, entire sections of the glass window might be made from one piece of glass. Where cost is less of a concern, glass panels may be installed instead.
Cathedral glass was originally manufactured for use in church windows but is now also made for commercial and private buildings, especially when symbolism is desired. Cathedral glass can be purchased in various sizes and shapes for any type of structure from small decorative panels for homes to large banks of windows for schools or hospitals.
Glass windows were added to certain Medieval Period stone castles, but not all. Windows might have wooden shutters, horn panes, oiled fabric, oiled skins, or no shutters at all. Stained glass is always beautiful, whether in a castle, a religious setting, or a contemporary window. It is simply part of our culture that stains its way into history and legend.
The first recorded use of stained glass was by Celidonius, a Roman artist who worked around 400 AD. He painted pictures on translucent sheets of glass which were then inserted into windows as frames. The colors of the paintings could be any one of several different pigments mixed with water and placed onto the glass surface - including red, green, blue, and white. This is how colored glass can preserve memories from the past.
In the 11th century, French monks began using colored pieces of glass in the tracery (the geometric patterns used in place of stone or wood for shaping the light) of their church windows. By the 13th century, stained glass was being made in England too. But it wasn't until the late 14th century that fully transparent windows became available, so for most of the Medieval period, castle builders had only limited access to color.
Starting in the 15th century, more and more wealthy landowners built their own houses instead of renting rooms in a townhouse or manor house.