The process used to render glass, iron, etc., less brittle, performed by allowing them to cool very gradually from a high heat.
The burning of metallic colors into glass, earthenware, etc.
After glass has been worked with heat, it will have residual stress within from temperature differences. Annealing is the process of heating the glass very slowly to a set temperature determined by the make and type of glass. It is held at this heat for a soaking period, during which the glass relaxes all stress, but does not change shape, or slump. It is then cooled very slowly to room temperature. Small work can be successfully annealed with the torch at the time of completion.