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
Architectural glass which it is carried by a system of rollers. The polished plate glass process starts with sheet or rolled plate glass. This glass is dimensionally inaccurate and often created visual distortions. These rough panes were ground flat and then polished clear. This was a fairly expensive process. Before the float process, mirrors were plate glass as sheet glass had visual distortions that were akin to those seen in amusement park or funfair mirrors. The elaborate patterns found on figured (or 'Cathedral') rolled-plate glass are produced in a similar fashion to the rolled plate glass process except that the plate is