Architectural glass light in industrial factories. Annealed glass is glass without internal stresses caused by heat treatment, i.e., rapid cooling, or by toughening or heat strengthening. Glass becomes annealed if it is heated above a transition point then allowed to cool slowly, without being quenched. Float glass is annealed during the process of manufacture. However, most toughened glass is made from float glass that has been specially heat-treated. Annealed glass breaks into large, jagged shards that can cause serious injury and is considered a hazard in architectural applications. Building codes in many parts of the world restrict the use of annealed glass
Photosensitive glass naked eye (i.e. gold or silver) are in the glass. These microscopic particles move and grow when heated to form the photographic image itself. The process is similar to camera film, however a "negative" is placed on top of the photosensitive glass and then exposed to ‘’’ultraviolet’’’ light. Camera film, of course, would be exposed to ordinary visible light. Then there is a special process for the exposed photosensitive glass. The glass is reheated then in a kiln and postbaked for several hours. The image then "appears" within the special exposed glass as if by magic. The heated piece of