In traditional glass blowing, molten glass is first created by heating a combination of soda ash, potash, limestone and sand to over 2000 degrees Fahrenheit (1093.3 Celcius.) When using the oldest technique, free-blowing, the glass blower spools a portion of molten glass on to the end of a blowpipe, forming a gather, or blob of molten glass. The blower then puffs air through the pipe to expand the glass into a bubble of the desired size. From this point, various tools are employed to produce the design the blower has envisioned.
The marver, a flat, thick steel surface, is used to cool and shape the glass. Tweezers, paddles, jacks and shears are used variously to pull out glass formations, flatten areas and cut and shape the glass. Glass that is not cooled properly can shatter dangerously due to thermal stress. Finished glass pieces are placed in an annealing oven to cool down at a safe temperature, a process that can take hours or days, depending on the size of the finished product. Individual glass blowers often develop their own workspaces and techniques, designed to suit their way of working, and methods of creation.
Modern glass workers, like those of old, create everything from speciality artwork to utilitarian items. Creating hand blow glass art in unique shapes or made-to-order is a staple of many glass studios, but some may also use a glass-molding technique to decrease work time and increase production of popular items. As the name implies, with glass-molding the molten glass is blown into a pre-made mold instead of being fashioned by hand.