The glassblower begins to form a glass piece by dipping a blow pipe or blow tube into a furnace of molten glass. The glass taken is in liquid form and so hot that it appears white. The molten glass is inflated into a bubble by use of the blowpipe, and takes different shape and thickness as it is rolled onto the marver (a slab of steel or marble) where its skin can cool. The glassblower will then use the "glory hole" to reheat the glass between steps. Temperature control and use and pressure of tools, such as shears, blocks, tweezers, paddles and seers, are strategically combined to form the shape. In the final stage, the piece is put into an annealer to cool and harden.
Glass blowing is used to create art pieces for decorative or functional use, and the craft can be taken up as a profession or hobby. Vases, bowls, platters, goblets and decorative ornaments are common, as are beads and jewelry. These items can retail at high prices with the tag "hand blown," indicating a professional glass blower formed the piece. This artwork is equated with sculptures or paintings because of the time and skill required. Glass blowing is also used in science to fabricate and repair glass apparatus.
Blown glass pieces often display vibrant colors and patterns in addition to their smooth curves. Color and shape are added gradually throughout the process, which can range in time, depending on the desired finished product as well as skill of the glass blower. The glass used for blowing comes in sticks called canes and is available in a wide range of colors. Once the shape of the piece is complete and the bottom is flattened with the paddle, more colors, patterns, and other decorative touches can be added to the piece by using different canes.
The most common historical information found on glass blowing reveals that it originated in Mesopotamia, where potters fired their clay into glass, fusing sand and minerals. Fragments of glass vases found in Mesopotamia date back to the 16th century BC. There is also evidence of other ancient glassmaking activities emerging independently in Mycenae (Greece), China and North Tyrol around this time. The popularity of the craft has shined and dimmed throughout history under the various kingdoms and empires of the world. The first glass-making instructional guide dates back to 600 BC, in tablets from the library of the Assyrian king Ashurbanipal (669-626 BC). Glass making was also a significant craft during the Roman Empire. Thereafter, it grew as an art in the Islamic world. Later, kings and queens during the Italian Renaissance highly regarded blown glass creations. The British Empire's glass blowing traditions came to the New World with the first colonists, some of whom were glassblowers by trade.
Glass blowing requires study, training and practice. Glass blowing courses often refrain from allowing first-time students to directly work with all the equipment, since working with such heat makes it a dangerous craft. While it is not impossible to set up a glass blowing work station at home, it is better for novices to practice in professional studios or glassblowing facilities, where the three types of furnaces required, wide work space, and trained professionals are available. Also, glassblowing facilities must adhere to local, state, and federal regulation for personal, property and environmental protection.
Glass blowing requires safety precautions. Burns and cuts are a possibility when working with molten glass. If you attempt glass blowing, use safety goggles at all times; wear gloves. Also, be sensible about clothing---don't wear open-toed shoes, loose jewelry or thin materials. Know the location of exits, fire alarms, telephone, fire extinguishers, safety and first-aid equipment, and gas shut-off valves.