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Acid Etching - This process for the decoration of glass involves the application of hydrofluoric acid to the glass surface. Hydrofluoric acid vapors or baths of hydrofluoric acid salts may be used to give glass a matte, frosted appearance (similar to that obtained by surface sandblasting), as found in lighting glass. Coating the glass with wax and then inscribing the desired pattern through the wax layer can produce glass designs. When applied, the acid will corrode the glass but not attack the wax-covered areas.

Annealing or Anneal - The process of slowly cooking a completed object in the furnace. The furnace is called an annealer or a Lehr. This is an integral part of glassmaking because the glass will be highly strained if it reaches room temperature too quickly and may break.

Annealing Oven - The process of gradual cooling of the outside and the inside of the molten glass to assure that the glass won’t cool to fast causing cracks or breaks.

Annealing Point - The temperature at which internal stresses in glass are significantly reduced. In the annealing operation, glass is gradually cooled from above the annealing point temperature to below the strain point temperature. This slow cooling relieves residual thermal stresses that would develop if the glass were allowed to cool in an uncontrolled manner.

Antique Glass - Glass with an uneven surface texture and bubbles inside produced using antique methods in order to obtain the appearance of glass made before the development of industrial processes. It may be drawn or produced from mouth-blown cylinders.

Assistant - The glassworker that works directly for the Gaffer. In some situations, there may be several assistants depending on the size of the project.

At-The-Fire - The process of reheating a blown glass object at the glory hole during manufacture, to permit further inflation and/or manipulation with tools.

Aventurine - Glass that contains copper flakes that give the appearance of gold.