Glassblowing is a glassforming technique that involves inflating the molten glass into a bubble, or parison, with the aid of the blowpipe, or blow tube. A person who blows glass is called a glassblower, glassmith, or gaffer (wikipedia). Besa Lighting among other lighting suppliers, specializes in this art and produces high-quality glass pendants, wall sconces, ceiling and outdoor fixtures.
The transformation of raw materials into glass takes place around 2400°F (1315°C); the glass emits enough heat to appear almost white hot. The glass is then left to "fine out" (allowing the bubbles to rise out of the mass), and then the working temperature is reduced in the furnace to around 2000°F (1100°C). At this stage, the glass appears to be a bright orange color. Though most glassblowing is done between 1600–1900°F (870–1040°C), "Soda-lime" glass remains somewhat plastic and workable as low as 1350°F (730°C). Annealing is usually done between 800–900°F (430–480°C).
Glassblowing involves three furnaces. The first, which contains a crucible of molten glass, is simply referred to as "the furnace." The second is called the "glory hole", and is used to reheat a piece in between steps of working with it. The final furnace is called the "lehr" or "annealer", and is used to slowly cool the glass, over a period of a few hours to a few days, depending on the size of the pieces. This keeps the glass from cracking due to thermal stress. Historically, all three furnaces were contained in one, with a set of progressively cooler chambers for each of the three purposes. Many glassblowing studios in Mexico and South America still employ this method.
All Besa luminaires feature handcrafted
glass in almost astounding variety! Traditionally, glass has been a primary material used in
fine luminaires. The glass for each Besa product is handcrafted using traditional methods,
passed down from generation to generation. The personal experience and artistry of the
individual glass-maker determines the quality of the final object…and Besa’s glass
craftsman are some of the most experienced and skilled. Handcrafted glass offers beauty
while still effectively directing or diffusing the light output of the fixture. This traditional art
adds real value to your contemporary lighting and with Besa, you’re sure to go with one of
the best there is.