Glass bead making

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Lampworking-closeup Lampworking-closeup.jpg
Lampworking-closeup
Lampwork glass beads Lampwork2.jpg
Lampwork glass beads

Glass bead making has long traditions, with the oldest known beads dating over 3,000 years. [1] [2] Glass beads have been dated back to at least Roman times. Perhaps the earliest glass-like beads were Egyptian faience beads, a form of clay bead with a self-forming vitreous coating. Glass beads are significant in archaeology because the presence of glass beads often indicate that there was trade and that the bead making technology was being spread. In addition, the composition of the glass beads could be analyzed and help archaeologists understand the sources of the beads. [3]

Contents

Common types of glass bead manufacture

Glass beads are usually categorized by the method used to manipulate the glass – wound beads, drawn beads, and molded beads. There are composites, such as millefiori beads, where cross-sections of a drawn glass cane are applied to a wound glass core. A very minor industry in blown glass beads also existed in 19th-century Venice and France.

Wound glass beads

Probably the earliest beads of true glass were made by the winding method. Glass at a temperature high enough to make it workable, or "ductile", is laid down or wound around a steel wire or mandrel coated in a clay slip called "bead release". The wound bead, while still hot, may be further shaped by manipulating with graphite, wood, stainless steel, brass, tungsten or marble tools and paddles. This process is called marvering, a term derived from the French marbrer, 'to marble'. It can also be pressed into a mold in its molten state. While still hot, or after re-heating, the surface of the bead may be decorated with fine rods of colored glass called stringers creating a type of lampwork bead.

Drawn glass beads

The drawing of glass is also ancient. Evidence of large-scale drawn-glass bead making has been found by archeologists in India, at sites like Arekamedu dating to the 2nd century CE. The small drawn beads made by that industry have been called Indo-Pacific beads, because they may have been the single most widely traded item in history—found from the islands of the Pacific to Great Zimbabwe in southern Africa. [4]

There are several methods for making drawn beads, but they all involve pulling a strand out of a gather of glass in such a way as to incorporate a bubble in the center of the strand to serve as the hole in the bead. In Arekamedu this was accomplished by inserting a hollow metal tube into the ball of hot glass and pulling the glass strand out around it, to form a continuous glass tube. In the Venetian bead industry, molten glass was gathered on the end of a tool called a puntile ("puntying up"), a bubble was incorporated into the center of a gather of molten glass, and a second puntile was attached before stretching the gather with its internal bubble into a long cane. The pulling was a skilled process, and canes were reportedly drawn to lengths up to 200 feet (61 m) long. The drawn tube was then chopped, producing individual drawn beads from its slices. The resulting beads were cooked or rolled in hot sand to round the edges without melting the holes closed; were sieved into sizes; and, usually, strung onto hanks for sale.

The most common type of modern glass bead is the seed bead, a small type of bead typically less than 6 mm (0.24 in), traditionally monochrome, and manufactured in very large quantities. They are a modern example of mechanically drawn glass beads. Seed beads, so called due to their tiny, regular size, are produced in the modern day from machine-extruded glass. Seed beads vary in shape; though most are round, some, such as Miyuki delicas, resemble small tubes.

Molded beads

Pressed glass beads Pressedglass.jpg
Pressed glass beads

Pressed or molded beads are associated with lower labour costs. These were commonly produced in the Czech Republic in the early 20th century. Thick glass rods are heated to molten and fed into a complex apparatus that stamps the glass, including a needle that pierces a hole. The beads again are rolled in hot sand to remove flashing and soften seam lines. By making canes (the glass rods fed into the machine) striped or otherwise patterned, the resulting beads can be more elaborately colored than seed beads. One "feed" of a hot rod might result in 10–20 beads, and a single operator can make thousands in a day. Glass beads are also manufactured or moulded using a rotary machine where molten glass is fed in to the centre of a rotary mould and solid or hollow glass beads are formed.

The Bohemian glass industry was known for its ability to copy more expensive beads, and produced molded glass "lion's teeth", "coral", and "shells", which were popular in the 19th and early 20th century Africa trade.

Lampwork beads

Lampworked dichroic glass bead showing thin film application Dichroicclose.jpg
Lampworked dichroic glass bead showing thin film application
Furnace glass beads Furnaceglass.jpg
Furnace glass beads

A variant of the wound glass bead making technique, and a labor-intensive one, is what is traditionally called lampworking. In the Venetian industry, where very large quantities of beads were produced in the 19th century for the African trade, the core of a decorated bead was produced from molten glass at furnace temperatures, a large-scale industrial process dominated by men. The delicate multicolored decoration was then added by people, mostly women, working at home using an oil lamp or spirit lamp to re-heat the cores and the fine wisps of colored glass used to decorate them. These workers were paid on a piecework basis for the resulting lampwork beads. Modern lampwork beads are made by using a gas torch to heat a rod of glass and spinning the resulting thread around a metal rod covered in bead release. When the base bead has been formed, other colors of glass can be added to the surface to create many designs. After this initial stage of the bead making process, the bead can be further fired in a kiln to make it more durable.

Modern bead makers use single or dual fuel torches, hence the more modern term flameworked. Unlike a metalworking torch, or burner, a flameworking torch is usually "surface mix"; that is, the oxygen and fuel (typically propane, though natural gas is also common) is mixed after it comes out of the torch, resulting in a quieter tool and less dirty flame. Also unlike metalworking, the torch is fixed, and the bead and glass move in the flame. American torches are usually mounted at about a 45-degree angle, a result of scientific glassblowing heritage; Japanese torches are recessed, and have flames coming straight up, like a large bunsen burner; Czech production torches tend to be positioned nearly horizontally.

Dichroic glass beads

Dichroic glass is used to produce high-end art beads. Dichroic glass has a thin film of metal fused to the surface of the glass, resulting in a surface that has a metallic sheen that changes between two colors when viewed at different angles. Beads can be pressed, or made with traditional lampworking techniques. If the glass is kept in the flame too long, the metallic coating will turn silver and burn off.

Furnace glass

Italian glass blowing techniques, such as latticinio and zanfirico, have been adapted make beads. Furnace glass uses large decorated canes built up out of smaller canes, encased in clear glass and then extruded to form the beads with linear and twisting stripe patterns. No air is blown into the glass. These beads require a large scale glass furnace and annealing kiln for manufacture.

Lead crystal

Lead crystal beads are machine-cut and polished. Their high lead content makes them sparkle more than other glass, but also makes them inherently fragile.

Other methods

Lead glass (for neon signs) and, especially borosilicate is available in tubing, allowing for glass blown beads. [5] (Soda-lime glass can be blown at the end of a metal tube, or, more commonly wound on the mandrel to make a hollow bead, but the former is unusual and the latter not a true mouth-blown technique.) In addition, beads can be fused from sheet glass or using ground glass.

Modern Ghana has an industry in beads molded from powdered glass. Also in Africa, Kiffa beads are made in Mauritania, historically by women, using powdered glass that the bead maker usually grinds from commercially available glass seed beads and recycled glass.

Molded ground glass, if painted into the mold, is called pate de verre, and the technique can be used to make beads, though pendants and cabochons are more typical. Lampwork (and other) beads can be painted with glass paints.

See also

Related Research Articles

<span class="mw-page-title-main">Bead</span> Small decorative object with central hole

A bead is a small, decorative object that is formed in a variety of shapes and sizes of a material such as stone, bone, shell, glass, plastic, wood, or pearl and with a small hole for threading or stringing. Beads range in size from under 1 millimeter (0.039 in) to over 1 centimeter (0.39 in) in diameter.

<span class="mw-page-title-main">Glassblowing</span> Technique for forming glass

Glassblowing is a glassforming technique that involves inflating molten glass into a bubble with the aid of a blowpipe. A person who blows glass is called a glassblower, glassmith, or gaffer. A lampworker manipulates glass with the use of a torch on a smaller scale, such as in producing precision laboratory glassware out of borosilicate glass.

<span class="mw-page-title-main">Studio glass</span> Modern use of glass as an artistic medium

Studio glass is the modern use of glass as an artistic medium to produce sculptures or three-dimensional artworks in the fine arts. The glass objects created are intended to make a sculptural or decorative statement, and typically serve no useful function. Though usage varies, the term is properly restricted to glass made as art in small workshops, typically with the personal involvement of the artist who designed the piece. This is in contrast to art glass, made by craftsmen in factories, and glass art, covering the whole range of glass with artistic interest made throughout history. Both art glass and studio glass originate in the 19th century, and the terms compare with studio pottery and art pottery, but in glass the term "studio glass" is mostly used for work made in the period beginning in the 1960s with a major revival in interest in artistic glassmaking.

<span class="mw-page-title-main">Seed bead</span>

Seed beads or rocailles are uniformly shaped, spheroidal beads ranging in size from under a millimeter to several millimeters. Seed bead is also a generic term for any small bead. Usually rounded in shape, seed beads are most commonly used for loom and off-loom bead weaving. They may be used for simple stringing, or as spacers between other beads in jewelry.

<span class="mw-page-title-main">Lampworking</span>

Lampworking is a type of glasswork in which a torch or lamp is used to melt the glass. Once in a molten state, the glass is formed by blowing and shaping with tools and hand movements. It is also known as flameworking or torchworking, as the modern practice no longer uses oil-fueled lamps. Although lack of a precise definition for lampworking makes it difficult to determine when this technique was first developed, the earliest verifiable lampworked glass is probably a collection of beads thought to date to the fifth century BCE. Lampworking became widely practiced in Murano, Italy in the 14th century. As early as the 17th century, itinerant glassworkers demonstrated lampworking to the public. In the mid-19th century lampwork technique was extended to the production of paperweights, primarily in France, where it became a popular art form, still collected today. Lampworking differs from glassblowing in that glassblowing uses a furnace as the primary heat source, although torches are also used.

<span class="mw-page-title-main">Millefiori</span> Glasswork technique

Millefiori is a glasswork technique which produces distinctive decorative patterns on glassware. The term millefiori is a combination of the Italian words "mille" (thousand) and "fiori" (flowers). Apsley Pellatt in his book Curiosities of Glass Making was the first to use the term "millefiori", which appeared in the Oxford English Dictionary in 1849; prior to that, the beads were called mosaic beads. While the use of this technique long precedes the term "millefiori", it is now most frequently associated with Venetian glassware.

<span class="mw-page-title-main">Borosilicate glass</span> Glass made of silica and boron trioxide

Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion, making them more resistant to thermal shock than any other common glass. Such glass is subjected to less thermal stress and can withstand temperature differentials without fracturing of about 165 °C (300 °F). It is commonly used for the construction of reagent bottles and flasks, as well as lighting, electronics, and cookware.

<span class="mw-page-title-main">Cathedral glass</span>

Cathedral glass is the name given commercially to monochromatic sheet glass. It is thin by comparison with 'slab glass', may be coloured, and is textured on one side. The name draws from the fact that windows of stained glass were a feature of medieval European cathedrals from the 10th century onward.

<span class="mw-page-title-main">Blowpipe (tool)</span> Tool used to direct a stream of gas

The term blowpipe refers to one of several tools used to direct streams of gases into any of several working media.

<span class="mw-page-title-main">Venetian glass</span> Glassmaking tradition from Venice, Italy

Venetian glass is glassware made in Venice, typically on the island of Murano near the city. Traditionally it is made with a soda–lime "metal" and is typically elaborately decorated, with various "hot" glass-forming techniques, as well as gilding, enamel, or engraving. Production has been concentrated on the Venetian island of Murano since the 13th century. Today Murano is known for its art glass, but it has a long history of innovations in glassmaking in addition to its artistic fame—and was Europe's major center for luxury glass from the High Middle Ages to the Italian Renaissance. During the 15th century, Murano glassmakers created cristallo—which was almost transparent and considered the finest glass in the world. Murano glassmakers also developed a white-colored glass that looked like porcelain. They later became Europe's finest makers of mirrors.

<span class="mw-page-title-main">Foundry</span> Factory that produces metal castings

A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron. However, other metals, such as bronze, brass, steel, magnesium, and zinc, are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed.

<span class="mw-page-title-main">Chevron bead</span> Type of glass beads

Chevron beads are special glass beads; the first specimens of this type were created by glass bead makers in Venice and Murano, Italy, toward the end of the 14th century. The first examples were invented by Marietta Barovier. They may also be referred to as rosetta, or star beads. The term rosetta first appeared in the inventory of the Barovier Glass works in Murano, in 1496, in context with beads as well as with other glass objects.

<span class="mw-page-title-main">Murrine</span> Colored patterns made in glass

Murrine are colored patterns or images made in a glass cane that are revealed when the cane is cut into thin cross-sections. Murrine can be made in infinite designs from simple circular or square patterns to complex detailed designs to even portraits of people. One familiar style is the flower or star shape which, when used together in large numbers from a number of different canes, is called millefiori.

<span class="mw-page-title-main">Murano beads</span> Glass beads influenced by Venetian glassmakers

Murano beads are intricate glass beads influenced by Venetian glass artists. Since 1291, Murano glassmakers have refined technologies for producing beads and glasswork such as crystalline glass, enamelled glass (smalto), glass with threads of gold (aventurine), multicolored glass (millefiori), milk glass (lattimo) and imitation gemstones made of glass.

<span class="mw-page-title-main">Caneworking</span> Glassblowing technique for making glass rods with several colored patterns

In glassblowing, cane refers to rods of glass with color; these rods can be simple, containing a single color, or they can be complex and contain strands of one or several colors in pattern. Caneworking refers to the process of making cane, and also to the use of pieces of cane, lengthwise, in the blowing process to add intricate, often spiral, patterns and stripes to vessels or other blown glass objects. Cane is also used to make murrine, thin discs cut from the cane in cross-section that are also added to blown or hot-worked objects. A particular form of murrine glasswork is millefiori, in which many murrine with a flower-like or star-shaped cross-section are included in a blown glass piece.

<span class="mw-page-title-main">Oxy-fuel welding and cutting</span> Metalworking technique using a fuel and oxygen

Oxy-fuel welding and oxy-fuel cutting are processes that use fuel gases and oxygen to weld or cut metals. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903. Pure oxygen, instead of air, is used to increase the flame temperature to allow localized melting of the workpiece material in a room environment.

Glass production involves two main methods – the float glass process that produces sheet glass, and glassblowing that produces bottles and other containers. It has been done in a variety of ways during the history of glass.

A glossary of terms used in glass art

<span class="mw-page-title-main">History of glass</span>

The history of glass-making dates back to at least 3,600 years ago in Mesopotamia. However, most writers claim that they may have been producing copies of glass objects from Egypt. Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt. The earliest known glass objects, of the mid 2,000 BCE, were beads, perhaps initially created as the accidental by-products of metal-working (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing. Glass products remained a luxury until the disasters that overtook the late Bronze Age civilizations seemingly brought glass-making to a halt.

<span class="mw-page-title-main">Glass art</span> Art, substantially or wholly made of glass

Glass art refers to individual works of art that are substantially or wholly made of glass. It ranges in size from monumental works and installation pieces to wall hangings and windows, to works of art made in studios and factories, including glass jewelry and tableware.

References

  1. "Glass Online: The History of Glass". Archived from the original on April 15, 2011. Retrieved 2007-10-29.
  2. Gowlett, J.A.J. (1997). High Definition Archaeology: Threads Through the Past: World Archaeology Volume 29 Issue 2. Routledge. ISBN   0-415-18429-0.
  3. Glover, I. C., & Bellina, B. (2011). Ban Don Ta Phet and Khao Sam Kaeo: The Earliest Indian Contacts Re-assessed. Early Interactions Between South and Southeast Asia: Reflections on Cross-cultural Exchange
  4. Kanungo, A.K. 2004. Glass Beads in Ancient India and Furnace-Wound Beads at Purdalpur: An Ethnoarchaeological Approach. Asian Perspectives 43(1):123–150.
  5. Dunham, Bandhu Scott (1994). Contemporary lampworking : a practical guide to shaping glass in the flame. Prescott, Ariz.: Salusa Glassworks. ISBN   9780934252560.