Editing Stained glass (section)

=== Cylinder or mouth-blown ('muff') glass ===
[[Glassblowing|Using a blow-pipe]], a glass maker will gather a glob of molten glass that was taken from the pot heating in the furnace. The 'gather' is formed to the correct shape and a bubble of air blown into it. Using metal tools, molds of wood that have been soaking in water, and gravity, the gather is manipulated to form a long, cylindrical shape. As it cools, it is reheated so that the manipulation can continue. During the process, the bottom of the cylinder is removed. Once brought to the desired size it is left to cool. One side of the cylinder is opened, and the cylinder is then put into another oven to quickly heat and flatten it, and then placed in an [[Annealing (glass)|annealer]] to cool at a controlled rate, making the material more stable. "Hand-blown" or "mouth-blown" cylinder (also called muff glass) and crown glass were the types used in the traditional fabrication of stained-glass windows.