General bead making methods

After designing a piece, a lampworker must carefully plan how to construct it. Once ready to begin, the lampworker slowly introduces glass rod or tubing into the flame to prevent cracking from thermal shock. The glass is heated until molten, wound around a specially coated steel, or stainless steel mandrel, forming the base bead. The coating is an anti-fluxing bead release that will allow the bead to be easily removed from the mandrel. It can then be embellished or decorated using a variety of techniques and materials. All parts of the work piece must be kept at similar temperatures in case they shatter. Once finished the piece must be annealed in an oven to prevent cracking or shattering.
Annealing, in glass terms, is heating a piece until its temperature reaches a stress-relief point, that is, a temperature at which the glass is still too hard to deform, but is soft enough for internal stresses to ease. The piece is then allowed to heat-soak until its temperature is uniform throughout. The time necessary for this depends on the type of glass and thickness of the thickest section. The piece is then slowly cooled at a predetermined rate that allows consistent cooling throughout the entire piece, until its temperature is below the critical point at which internal stresses can't be generated, and then can safely be dropped to room temperature. This process relieves the internal stresses, resulting in a piece that should last for many years. Glass that has not been annealed may crack or shatter due to a seemingly minor temperature change or other shock.

▪ Preparing the mandrel - The bead maker starts by dipping a mandrel, or wire (stainless steel wire, cut into approximately 30cm lengths) into a clay/silica based substance (commonly referred to as "bead release") and letting it dry.
▪ Heating rod and mandrel - The flameworker selects rods of glass to heat in the flame of the torch. When both glass and mandrel are sufficiently hot, the bead maker starts rotating the mandrel while allowing the glass to wind upon it.
▪ Shaping the bead - Beads are shaped using a combination of heat, gravity and tools such as graphite paddles, mashers, tweezers, and picks. Presses to create shapes and indent patterns into the glass are also used.
▪ Decorating the bead - Beads can be decorated by melting stringers, or fibres of glass on the surface, creating dots or lines. With a sharp pointed tool, feathers, hearts or other designs may be produced. Metal decorations of copper, silver, gold, palladium and platinum are applied as metal leaf, wire, mesh or fuming.
▪ Striking - If silver based colours are used (striking colours), the bead must be heated for a few moments in the torch flame or kiln to allow crystals to reform in the glass. This temperature is slightly above the stress relief point.
▪ Annealing - Once completed, beads should be heated to 470-560 deg C (depending on glass type), until the piece reaches its "stress relief point", held at that temperature for a short time, then slowly cooled to avoid thermal shock.
▪ Cold working - The cooled bead can be further decorated. Standard cold working techniques can be employed such as sandblasting, faceting and polishing. Etching the finished piece with acid leaves a matte finish.

Beads can be sandblasted, or they can be faceted, using lapidary techniques. Chevron beads are multi-layer beads once exclusively made using hot-shop techniques to produce the original tubing; but now some lampworkers make similar designs on their torches before lapping the ends to reveal the various layered colours. As torches get bigger and more powerful, the convergence between lampworking and furnace (or "off-hand") glass continues to increase.
Fuming is a technique that consists of heating silver or gold in the flame, so that the metals vaporize or "fume" microscopically thin layers of particles onto the glass. These particles stick to the hot glass surface changing its colour with interesting effects. Silver turns clear glass into a yellowish colour, giving shades of blues and greens when backed with a dark colour, while gold turns clear glass shades of pinks and reds. The precious metal coating becomes increasingly visible the more the glass is fumed.

Lampworked beads have generally been the provenance of Italian, and later, Bohemian lampworkers for about the last four hundred years. The techniques were often kept secret. Bead making in other parts of the western world started to gain in popularity in the last 30 or so years (I need more information for this section, if anyone can help out here I would appreciate it).

Beads have been made in Japan for about 400 years and are known as "Tonbo-dama", literal translation in English is "Dragonfly-Ball", but also means "glass bead". Some believe the name originated because the surface was decorated with a circle pattern and it looked like the eye of a dragonfly, however there are also many other stories about the origin of the name, none of which can be verified. Tonbo-dama arrived in Japan in the Edo period (1603 to 1868) from Nanban trade (Southern barbarian trade), the trade with Portugal and Spain (Image: A group of Portuguese Nanban foreigners, 17th century, Japan). They have been made in Japan since then, for about 400 years.
These beads were originally made using a "Hot volcano" type of furnace, shaped somewhat like a volcano, hence the name, where a concentrated flame is emitted from the top opening. Modern Japanese burners are more like Bunsen burners, specially designed for use with locally made glass (e.g. Kinari, Satake).