Bevel
A bevel is a piece of glass whose edges have been ground at an angle and polished. The sloping edge acts like a prism, breaking daylight into small spectrum colours and throwing them across the wall or floor. In decorative glass the term usually means one of the shaped bevels, such as squares, diamonds, triangles and curved pieces, that are assembled into patterns.
Bevels are cut from thick plate or float glass and ground in several stages on a series of wheels, then polished with a fine abrasive until the edge is clear. A cluster of several bevels, set together in a pattern, is called a bevel cluster, and clusters are usually the centrepiece of a decorative door panel.
Bevelled glass is a form of leaded light. Traditionally the bevels are held in lead came, and the panel is made up piece by piece. Modern overlay bevelled glass is built differently, with the bevels bonded to safety glass and the lead lines applied over the top. Leaded lights that must be double glazed have to be sealed inside the unit, whereas overlay bevels sit on the outside, where they can be touched.