ACID ETCHING: The process of etching the surface of glass with hydrofluoric acid creating a matte finish.

ALABASTER GLASS: A type of translucent glass similar to opal glass.

ALKALI: A soluble salt consisting mainly of potassium carbonate. Alkali is one of the essential ingredients of glass, generally accounting for about 15-20% of the batch. The alkali is a flux, which reduces the melting point of the major constituent of glass, silica.

ANCIENT GLASS: A term frequently used to mean all pre-Roman and ancient Roman period glass.

ANNEALING: The process of slowly cooling a completed object in an auxiliary part of the glass furnace, or in a separate furnace. This is an integral part of glass making. If a hot glass object is allowed to cool too rapidly, it will be highly strained by the time it reaches room temperature. In fact, it may break as it cools. Most glass has a stress range, a temperature range at which the glass will break if allowed to cool too quickly. Highly strained glasses break easily if subjected to mechanical or thermal shock.

ANNULAR: A disk shaped bead with a large diameter hole.

APPLIED DECORATION: Heated glass elements (such as canes, murrini, and trails) applied during manufacture to a glass object that is still hot, and either left in relief, heated, or marvered until they are flush with the surface.

ARGENTO, Italian, silver: Beads made with silver foil under a layer of clear or transparent colored glass, sometimes with a mix of transparent colors.

ART GLASS: (1) Several types of glass with newly developed surface textures, shaded colors, or casing, made in the United States from about 1870 and in Europe about 1880-1900; (2) more generally, any ornamental glassware made since the mid 19th century.

AV LENSES: Protective eyewear for flameworking. The finest quality protective eyewear, AV lenses eliminate 95% of the sodium flare, ultra-violet, and infra-red rays given off by the oxygen/propane fueled torch used by most flameworkers, available in a variety of levels of protection for different types of glass, and use.

AVENTURINA/GOLDSTONE,(Italian, "accident"): Glass batched with fine copper filings that goes through a process of heating and cooling until the copper filings create a crystallization effect. Aventurina glass was first created in Venice, Italy in the 15th century. Aventurina is available in gold (goldstone), blue (bluestone), and green (greenstone). Greenstone is created using chrome.

BEAD SEPERATOR/RELEASE: A liquid clay, (similar to kiln wash), used by glass beadmakers. Used to coat a mandrel, the bead is then made by winding molten glass around the coated area, when cool the clay allows the bead to be removed from the mandrel. Old beads, (and most beads made in Venice, Italy), are not made using bead release. Venetian glass beads are made using thin copper tubing. The beads are then cut off the tubing and put into an acid bath to eat away the metal tubing leaving the glass bead with a perfectly clean hole.

BLANK: Any cooled glass object that requires further forming or decoration to be finished.

BLOBBING: The technique of decorating hot glass by dropping onto the surface blobs of molten glass, usually of a different color or colors.

BLOCK: A block of wood, or graphite hollowed out to form a hemispherical recess. The block is used to form a gather into a sphere. There are bead, marble and button blocks available.

BOROSILICATE GLASS: A type of potash glass, borosilicate glass is dense, passes from the molten to rigid state quickly and is harder than soda, and lead glass. It is therefore extremely durable, commonly used for sculptural flameworking and pipe making. The COE of borosilicate glass is 34. The most widely known brands of colored borosilicate glass rods are Northstar and Glass Alchemy. Pyrex is a widely recognized brand of borosilicate glass used to make cookware.

BOTTLE GLASS: A common naturally colored dark greenish or brownish glass. The color is characteristic of glass that includes traces of iron found in the natural silica used as the major ingredient. Sometimes, additional iron, in the form of iron oxide (or other materials) is added to darken the color.

BUBBLES: A pocket of gas trapped during manufacture. The term is used for both bubbles introduced intentionally (also known as air traps or beads) and bubbles trapped accidentally during the casing and melting process. Very small bubbles are known as seeds.

BULLSEYE CANE: A type of murrine, that has two or more colors alternating to form concentric rings. Think of a many layered cased cane!

BULLSEYE GLASS: American glass made in Oregon, originally designed for stained glass Bullseye revolutionized the glass fusing movement by creating a line of "tested compatible" glass. Bullseye now makes glass rods designed with the flameworker in mind. Bullseye’s line of compatible glass has a COE of 90.

BURNER: A part of the torch where the flame is produced, more generally a glass workers torch.

CABLE: A patterned cane resembling the twisted strands of a rope. Two opaque rods are connected together overlapping 1 inch, cased in clear glass and then finally filigree rods are attached in the same manner all around the bundle. When twisted and pulled the internal rods appear as a larger cable inside fine threads created by the filigree canes.

CAKE BEAD, (Wedding Cake Bead, Italian, Fiorato, Flowers): A bead decorated with applied or embedded trailings (usually of gold aventurina) and roses resembling a decorated cake.

CALCEDONIO, (Italian, "chalcedony"): Glass marbled with brown, blue, green, and yellow swirls created by large amounts of silver nitrate in the glass. An imitation of chalcedony, agate, and other banded semi-precious stones. Calcedonio was first made in Venice in the late 15th century. A very specialized glass, it is rarely made today, held in similar regard to Aventurina glass by the Venetian's, the formula for making Calcedonio is kept secret by those who know how to make it.

CANE: A thin, composite rod consisting of groups of rods of different colors, which are bundled together, heated and fused, then pulled, or pulled and twisted. Thus forming a polychrome design that is visible when seen in the cross section or in the case of twisted cane through the length. The combinations are endless.

CASED CANE, traditionally called rose cane or leaf cane: A cane made with a dark transparent casing over a light opaque core. Used for creating the floral decoration on the classic Venetian Fiorato beads. A cased cane is made by warming a 1 inch length of a light opaque glass rod. Warm just enough so as not to thermal shock, but not enough to start to bend. Then take any medium to dark transparent color, (in most instances the darker colors are more effective because we will be stretching this cane out and so the darker colors stay more intense). Heat the transparent rod to molten and begin to case the opaque glass rod 1 inch from the cut end wrapping around the opaque rod and working towards the cut end. When you get to the end, punty the transparent rod to the opaque rod, giving you a handle at both ends. Heat the entire gather end to end and evenly around. When it is starting to flop, come out of the flame towards you, wait about ten seconds while continuing to turn so as not to allow gravity to pull the hot glass down, and then slowly begin to pull the two ends apart. It is important to pull slowly or the hot glass may drip. As the cane begins to cool you will want to pull progressively harder to keep the cane as even end to end as possible. The slower you pull the thicker the cane will be.

CASING, incasing: The application of a layer of glass over a layer of contrasting color. Most commonly clear or extremely light transparent glass layered over an internal core of glass.

CLEAR CASING: The application of one or more layers of clear glass over an internal core of glass. The clear layer in most cases magnifies internal decoration. The thicker the application of clear glass, the more magnification occurs.

COEFFICIENT OF EXPANSION (COE): Term used for the measured expansion and contraction rate of a type of glass based on the percentage of change during the heating and cooling process. Glass of differing types, (based on the raw materials used to make the batch), will have different rates of expansion and contraction. Glass with greater expansion capabilities has a higher COE rating. Glass that is of the same or very similar COE and that has the same basic raw ingredients in the batch is compatible and thereby workable with another glass made from the same basic ingredients. To be compatible glass must be of the same or very similar coefficient of expansion, viscosity, and annealing range. For some applications this general rule can be broken, but for others it becomes more important. When making glass beads COE becomes important, especially when incasing and most often concerning the core layer of the bead.

COIL BASE: A trail or thread of glass drawn out to form a ring or conical foot on which a glass vessel stands.

COLD WORKING: The collective term used to describe the many varied techniques used to alter or decorate a glass object when it is cold.

COLLAR: A band of applied glass around the rim of a vessel, or other glass object.

COLORED GLASS: Glass that is colored by either impurities in the basic ingredients in the batch, or techniques of coloring glass by one of three main processes. (1) Using a dissolved metallic oxide to impart a color throughout, (2) forming a dispersion of some substance in a colloidal state, and (3) suspending particles of pigments to form opaque colors.

COMBED DECORATION: A wavy, feathery, or zigzag pattern of decoration in two or more colors. The pattern is produced by applying a thread, or trailing of glass that is different in color to the base glass object. The trailings are then heated into the base, after which they are combed, dragged, or raked to achieve the desired affect.

COMPATIBILITY: Glass that is of the same or very similar COE. Glass that has the same basic raw ingredients in the batch, thereby making it compatible (workable) with another glass made from the same basic ingredients. To be compatible glass must be of the same or very similar coefficient of expansion, viscosity, and annealing range.

COMPATIBILITY TEST: For flameworking, the most commonly used is the Pull test, or Strand test. Heat two rods of glass, attach together overlapping them one inch, heat together without mixing or twisting, then pull into a thin straight cane. When cut off the rods, if the cane remains straight the two glasses are compatible. If the two glasses differ in linear expansion, the cane will be curved. The glass of greater linear expansion, (higher COE rating), will be on the inside of the curve because of its greater ability to bend. The greater the curve, the greater the difference between the two glasses. In some cases, if the glass is of great difference, one rod will pull out while the other cools thus not pulling as much if at all.

COMPOUND: In flameworked glass beads, compound means having two or more distinct layers of glass, one over the other.

CONTROLLER: An apparatus that holds a kiln, furnace, or annealing oven at a desired temperature. Ramping controllers allow you to set a program that changes temperature by a set number of degrees over a period of time automatically.

CORD: Accidental colorless streaks in the glass caused by local differences in refractive indexes. Poor mixing of the batch often produces cord.

CORE: Term used to describe the very center of a glass object, as in heating an object to core heat.

CORE FORMING: The technique of forming a vessel by winding, trailing or gathering molten glass around a core form supported by a steel rod or mandrel. After forming, the glass object is annealed, then removed from the mandrel and the core scraped clean. In pre-Roman times, the core is thought to have been made from animal dung mixed with clay.

CORNALINE D' ALEPPO, (Italian, " Aleppo, [Syria] carnelian"): White heart beads. Compound beads with two layers, usually transparent red or ruby over opaque white, yellow, green or pink. Created to imitate carnelian and coral.

COVERED TWIST: Think of a striped rose or leaf cane. This cane starts with an light colored opaque glass rod. Attach any number and combination of dark colored transparent rods overlapping 1 inch, (commonly done in rainbow colors). Work all the way around the central core rod so that it is completely covered, (the idea here is for the opaque rod to help make the transparent colors pop). Heat the bundle, when hot twist and pull.

COWHORN, (Troncono, Italian): The large end of a glass rod or cane that is shaped like the tapered horn of a cow. The cowhorns are the two ends of a pull of glass, while the glass is pulled to create an even thickness throughout the length, the two ends are commonly much thicker due to cooling as the length is pulled out.

CRACKING OFF: The process of detaching a glass object from the blowpipe, pontil or rod.

CRISTALLO, (Italian, crystal): A term first used in Venice in the 14th century to describe glass that resembles colorless rock crystal. Formerly most Venetian cristallo had a slight grayish, or brownish tint. True clear glass is the most difficult to make because it is necessary to create the complete absence of color.

CRIZZLING, crisseling: A chemical instability in glass caused by an imbalance in the ingredients of the batch, particularly an excess of alkali or a deficiency of stabilizer (usually lime). The instability of the glass results in an attack by atmospheric moisture, which produces a network of cracks in the surface. Crizzling can be slowed or halted, but it cannot be reversed.

CRUMB BEAD: Sometimes called sugar beads. A simple decorative technique that is created by rolling a molten hot core bead into multi-colored glass frit.

CRYSTAL: A popular term for colorless lead glass that has a high refractive index and consequently is particularly brilliant.

CULLET: (1) Raw glass or pieces of broken glass from a cooled melt; (2) scrap glass intended for recycling.

DECOLORIZER: A substance (such as manganese dioxide or cerium oxide) used to remove the greenish or brownish color in glass that results from iron impurities in the batch.

DEVITRIFICATION: (1) A process during which glass becomes partly crystallized as it cools from the molten state. In this instance caused from cooling too slowly. (2) The name of the crystals formed by this process. Devitrification can occur on the surface of a glass object as a result of unsuccessful annealing or accidental heating to a high temperature. It is not caused by chemical reaction between glass and its environment, which is known as weathering.

DICHROIC GLASS: Glass that is one color when seen by reflected light and another color when light shines through it. This is sometimes due to the presence of minute quantities of colloidal gold. Dichroic glass in use at present was first created for use in the NASA space program as a heat shield. Created in a vacuum-sealed environment by spraying three or more layers of metallic coating on the surface of the glass. The metallic coating is highly prone to burn out in the presence of an oxidizing flame. Dichroic glass was first used by the art glass movement in the early 1980's.

DIDYMIUM LENSES: Protective lenses for flameworking, didymium glasses eliminate 90% of the sodium flare and ultra-violet rays given off by the propane/oxygen fueled torch used by glassworkers. No longer the industry standard for protective eyewear. Replaced by the much more effective Aura and AV lenses. DRAWN GLASS BEAD: Beads manufactured in the hot shop using blowing techniques. A gather of glass is picked up on the end of a blowpipe, after marvering slightly a bubble is blown into the glass, layers of different colors can be added, then the glass is pulled, (drawn) by two glass workers into a long hollow cane, or tube. When cool the tube can be cut into various size beads, all with the same pattern. Finishing is done with lapidary equipment, generally grinding and tumbling, but can include fire polishing.

EFFETRE GLASS: This beautiful soft soda-lime glass is made on the Island of Murano in Venice, Italy. Formerly owned by the Moretti Family and thus called Moretti, the company changed hands in the 1980's. The name Effetre means "three F's", and stands for the three Ferro brothers who together bought the company, (although one brother recently left). Effetre glass is most frequently used for flameworking and glass beadmaking. Effetre glass has been made for hundreds of years in the same factory, it was created especially for beadmaking and comes in a wide range of colors. Effetre comes in 5mm-15mm thick rods as well as sheet form with a COE of 104-113.

EGYPTIAN BLUE: A synthetic material, copper calcium tetrasilicate, with a distinctive blue color. It is often confused with faience. Egyptian blue was made in ancient times, by heating together silica, and lime, with a copper-containing ingredient.

ENAMEL POWDER: A substance made of finely powdered glass with metallic oxides.

ENCASED GLASS: A glass object, such as a bead or paperweight, that is covered with one or more layers of clear glass.

END OF THE DAY BEAD: Term given to Venetian glass beads that were made using the scraps of glass rods and canes believed to have been swept off the floor at the end of the work day.

EYE BEAD, (hobnail, dot): A bead decorated with applied or embedded spots to resemble eyes. Eye beads were at one time thought to ward off the evil eye. Chinese Warring State’s beads are an example of an ancient intricate stratified eye bead sometimes containing hundreds of layered dots one upon another.

FACETING: The process of grinding and polishing a glass object to give the surface a pattern of planes or facets.

FAIENCE: An object made of a fired silica body covered with glaze, containing small amounts of alkali, and varying greatly in hardness depending on the degree of sintering. The term glassy faience is often used to describe a faience object in which the reactions have proceeded to such an extent that the glass phase defines the visual appearance of the material. It is thought that glass was first discovered while making faience.

FILIGRANA CANE (Italian, filagree): A cane made by casing a colored glass gather cased with clear then pulled while hot.

FILIGRANA, VETRO A FILAGRANA (Italian, "filigree glass"): The generic name for a glass object made with filigrana canes. For main types of filigrana glass, see vetro a fili, vetro a reticello, and vetro a retorti.

FINISHING: The process of completing the shaping or decoration of a glass object.

FIORATO BEAD, (Italian, flowers): A traditional Venetian glass bead also known as cake beads/wedding cake beads because they resemble a decorated cake. Decorated with applied or embedded trailings, (usually of gold leaf covered with clear glass later with aventurina), roses and spot flowers resembling forget me-nots.

FIRE POLISHING: The reintroducing of a glass object into the heat to melt the surface and eliminate superficial irregularities.

FIRING: The process of (1) heating the batch in order to fuse it into glass by exposing it to the required temperature in a crucible or pot, (2) reheating an unfinished glass object while it is being worked. The melting of the batch may require a temperature of approximately 2575 degrees.

FLAMEWORKING: The technique of making glass objects from rods or tubes. The glass rod when heated in the flame becomes soft and can be manipulated into a desired shape. Formerly, the source of the flame was an oil or paraffin fueled lamp used in conjunction with foot powered bellows (lampworking), today gas-fueled torches are used.

FLASHBACK ARRESTOR: Connects between the regulator and hose prevents the reverse flow of gases to the tank. Utilizes an internal reverse flow check valve and flame arrestor that quenches the flashback flame.

FLASHING: The application of a very thin layer of glass of one color over a layer of a contrasting color.

FLUTING: A decoration that consists of narrow, vertical grooves.

FLUX: A substance that facilitates fusion. For example, a flux is added to the batch in order to fuse the silica into glass. Potash and soda are fluxes.

FOOT-RING: A separate ring of glass added to the base of a vessel after the body is formed.

FOREST GLASS: Glass made in the rural glasshouses of central and northern Europe in the late Middle Ages and early modern period. Most forest glass was fluxed with potash derived from the wood that fueled the furnaces. The green color was caused by iron impurities in the sand that the batch was made from.

FOUNDING: The initial phase of melting batch. For most glass, the materials must be heated to a temperature of approximately 2450 degrees. This is followed by a maturing period, during which the molten glass cools to a working temperature of approximately 2000 degrees.

FRIT: (1) Batch ingredients such as sand and alkali that have been partially reacted by heating but not completely melted. After cooling the frit is ground into powder and completely melted; (2) Small particles of various colors of glass used to color or decorate a glass object. See reduction frit.

FRITTING: The process of making frit. See sintering.

FROSTING: (1) A matte finish produced by exposing a glass object to fumes of hydrofluoric acid; (2) a network of small surface cracks caused by weathering.

FURNACE: An enclosed structure for the production and application of heat. In glassmaking, furnaces are used for melting the batch, maintaining pots of glass in a molten state, and reheating partly formed objects at the gloryhole.

FUSING: (1) The process of founding or melting the batch; (2) heating pieces of glass in a kiln or furnace until they bond together; (3) heating enamels, powdered glass, frit, applied decoration, or layers of glass until they bond with the surface of the object.

GATHER: (noun) A mass of molten glass collected on the end of a blowpipe, pontil, gathering iron, or mandrel. (verb) To collect molten glass on the end of a tool.

GILDING: The process of decorating glass by the use of gold leaf.

GLASS: A homogeneous material with a random, liquid (non-crystalline) molecular structure. The process requires that the raw materials (batch) be heated to a temperature high enough to produce a completely fused melt. The glass, when cooled rapidly then becomes rigid without crystallizing.

GLASS SHEARS: A tool used to trim excess hot glass from an object during production. Also used to create decorative elements such as wings, feathers, and fins.

GOLD RUBY: Deep red or fuchsia glass colored by the addition of gold chloride to the batch.

GRAPHITE PAD: A flat usually square piece of graphite used for leaf/foil and glass pick up decoration.

GRAPHITE PADDLE: A shaping tool used by flameworkers, a small rectangular flat piece of graphite with a handle. Graphite is used because it does not shock the glass.

HAND PRESS, bead press: A tool shaped like a pair of pliers, with flat jaws containing a mold. A hand press can be of almost any shape including, flat, spherical, or leaf shaped.

HOT-FORMED, Hot-worked: A generic term used to describe glass that is manipulated while it is hot.

HYDROFLUORIC ACID: A highly corrosive acid that attacks silicates such as glass. Pure hydrofluoric acid dissolves glass, leaving a brilliant, acid polished surface.

ICE GLASS, crackle glass: A decorative effect that causes the surface of the glass to resemble cracked ice. This is achieved by plunging the glass while hot into cold water and withdrawing it quickly. The thermal shock causes small fissures in the surface creating a frosted and crackled appearance.

INCLUSIONS: A collective term for bubbles, precious metal, glass particles, and other material that have been added to the internal layer of a glass object for decorative effect.

INLAY: Term for any object embedded in the surface of a glass object.

INTARSA: See inlay.

INTERCALAIRE (French, inserted): The process of applying two layers of decoration, the first layer being covered by a thin skin (casing) of clear glass, which then serves as the surface for the second layer of decoration.

INTERNAL TWIST: A cane made by first making a bundle of one color, (as in a stringer), then flattened, striped with stringer. Proceed by drop or ball casing each flat surface covering the edges with a little clear casing so that you have a striped lollypop trapped within a ball of clear glass. Heat, and pull and twist. The finished cane looks much like seaweed. For this reason I always use it to decorate aquarium beads.

IRIDESCENCE: A rainbow like effect that changes depending on the angle from which it is viewed, or the angle of the light source. On ancient glass it is caused by interference effects of light reflected from several layers of weathering products. On certain 19th and 20th century glass objects, iridescence is deliberately achieved by the introduction of metallic substances, or by spraying the surface of the object with stannous chloride, or lead chloride, or the use of reduction frit, then re-heating the object in a reducing flame.

KILN, Annealing oven: An oven used to process a substance, by burning, drying, or heating. In contemporary glass working, kilns are used to fuse, form, slump, and anneal.

KILN FORMING: The process of fusing or shaping glass (usually in or over a mold) by heating the glass object in a kiln.

KUGLER GLASS: Made in Germany, mostly used for glass blowing, except for their reduction frit now occasionally used in bead making in the U.S. Kugler glass has a COE of 89-95.

LAMPWORKING: See Flameworking.

LATTICINO, LATTICINI, (Italian, "milk like threads"): From latte meaning milk. A glass cane made by bundling many filigrana canes together then heating, twisting, and pulling. Traditionally the term was only used to describe canes made of white filigree rods, a colored cane was called a reticello. Today in the U.S. the term latticini/latticino is used to describe any combination of filigree canes.

LATTIMO (Italian): Opaque white (milk) glass, usually made opaque by the addition of tin or arsenic to the batch.

LAUB AND BANDELWERK, (German, "leaf and strapwork"): A type of interlaced decoration consisting of foliage and strapwork.

LAUSHA GLASS: Glass rods and tubes made in Lausha, Germany especially for sculptural flameworking, the making of glass pens and some beadmaking. The COE is 95-110, some Lausha glass is compatible with Effetre glass, some with Kugler and Q-color. Compatibility of the palette changes due to a high aluminum content which changes batch to batch.

LEAD GLASS: It is relatively soft, and its refractive index gives off a lovely brilliance. For example Satake Japanese glass has a high lead content. It is heavier and more brilliant than Italian or American glass.

LEAF CANE: See cased cane.

LIME (Calcined limestone): Added to the glass batch in small quantities to add stability. Before the 17th century, when its beneficial effects became known, calcined limestone was introduced as an impurity in the raw materials.

LUSTER: A shiny metallic effect created by applying metallic oxides that have been dissolved in acid and mixed with an oily medium. Firing in an oxygen free oven at approximately 1150 F causes the metal to deposit a thin film that when clean has a distinctive shiny surface. Most often Stannous Chloride.

LUSTER POWDER: A powder made from ground colored mica flakes. Used to create iridescence or sparkle on the surface of the glass. Sometimes called Pixie dust or mother of pearl powder.

MANDREL: Thin (usually stainless steel, sometimes copper) wire used in flameworked glass beadmaking. The glass is wound as it melts, around a mandrel that has been coated with a clay release, when cool the bead is removed from the mandrel, which creates the hole in the bead. Available in various lengths and widths. In Venice, Italy mandrels are still made from thin copper tubing/wire not coated with a clay release. Instead the beads are cut off the end of the copper tubing and then put into an acid, which eats away the copper leaving behind the untouched glass bead.

MARBLED GLASS: Glass with streaks of two or more colors, resembling marble. Marbled glass was a Venetian specialty from the 15th-17th centuries.

MARQUETRY: A decorative technique created by applying pieces of glass to a hot glass object then heated and marvered into the surface.

MARVER (French, marbre, "Marble"): A smooth, flat surface, (originally made of marble, hence the name), used to shape molten glass; or the term for shaping molten glass on a marver, or paddle, as in, to marver.

MATTE FINISH: A non-shiny finish on a glass object created by, luster powder, sandblasting, tumbling, or acid etching. Tumbling gives a much more desirable finish to the beads, whereas acid etching can look too weathered, not unlike beach glass..

MELT: The fluid glass produced by melting a batch of raw materials.

METALLIC OXIDE: The oxide of a type of metal. Oxides are used to color glass and enamel powder, and to produce a luster or iridescent finish on glass. The resulting color depends primarily on the oxide used, but is also affected by the composition of the glass and the absence or presence of oxygen in the furnace.

MILLEFIORI (Italian,"1000 flowers"): Term especially used to describe complex murrine canes that resemble flowers, stars and chevron patterns.

MINOR BENCH BURNER: The most commonly used torch for making flameworked glass beads. A surface mix torch that uses propane/oxygen fuel well suited for soft glasswork.

MOLD: A form used to create a particular shape in a molten glass object.

MOSAIC GLASS: A glass object made from many small pieces of varicolored glass millefiori elements heated until they fuse together.

MURANO GLASS: Glass rods made by the Vetro Fond company of Mestre, Italy, (close to Murano and still part of Venice), with a COE of 104-108. Many colors are the same as the Effetre glass colors, with a few, very nice exceptions. Founded by one of the master glass batchers of the Moretti/Effetre factory who left to start his own factory when the Ferro brothers took over. Compatible with Effetre glass.

MURRINA (Italian): A slice of a complex murrine cane.

MURRINE (Italian): A complex cane that when viewed through the cross section reveals a desired figurative or other image, such as floral, fish, portrait, and initial cane. Murrine can be created in a torch or in the hot shop by bundling together glass stringer to create the desired image, heating, then pulling the cane to various widths.

MURRINO (Italian): The insertion of a murrina into a glass object.

NATRON: Sodium sesquicarbonate, originally from the Wadi el Natron region northwest of Cairo. It was commonly used by Roman glassmakers as the alkali constituent of the batch.

OBSIDIAN: A volcanic mineral form of natural glass. The first form of glass used by humans.

OPAL GLASS: Glass that resembles an opal, being translucent and white, with a grayish, yellowish, or bluish tint. Venetian glassworkers claim that true opal glass was produced by adding polenta, cauliflower or potatoes to the batch, the burning vegetables would create a natural gas which would create the unusual effect. The story goes that the opal batch didn’t come out as well when the factory workers were hungry as they would instead eat the vegetables! A colorful story to say the least.

OPENWORK: Glass objects made by creating a network of trails.

OPTIC MOLD: An open mold with a patterned interior in which molten glass can be inserted. Optic molds are used to create millefiori canes, chevron, and furnace beads.

ORO, Italian, Gold: Beads made with gold leaf under a layer of clear or transparent colored glass, sometimes with a mix of transparent colors.

OVERLAY: A layer of glass that covers a layer of different colored glass, often as a result of casing, or flashing.

OXIDIZING FLAME: An over abundance of oxygen in the torch flame, which causes the glass to bubble, creating a boiled appearance.

PEGGING: The process of pricking a glass object with a tool creating small air filled hollows. When covered with a second layer of glass the hollows become air traps.

PICK UP DECORATIONS: The technique of rolling a hot glass object in chips of glass then heating and marvering them into the surface of the object.

PLASTIC: The term for glass when it is in a workable, but not yet molten state.

PONTIL (French, "handle"): The pontil or punty is a tool (usually solid metal) used to hold a glass object while being worked, or before finishing.

POT, CRUCIBLE: A fire clay container used to hold the raw materials that make glass while they are fused together in the furnace.

POTASH: Potassium carbonate, an alternative ingredient to soda as a source of alkali in the batch. Potash glass is denser than soda glass; it passes from the molten to the rigid state more quickly. It is slightly more difficult to manipulate into elaborate forms. However, it is harder, stronger, and more brilliant. Borosilicate is potash glass.

POTASSIUM-LIME GLASS: A type of glass containing three major ingredients in varying proportions; silica 60-75%, potash 12-18%, and lime 5-12%. Forest glass is a common type of potassium-lime glass.

PRUNT: A blob of glass applied to a glass object as a decorative element, or to hold the glass object in the absence of a tool for a handle.

PYROMETER: Reads the temperature inside a kiln. A pyrometer does not control the kiln temperature.

Q-COLORS: Made in Germany, most frequently used for glass blowing, except for their line of reduction frit used occasionally for bead making. Q-colors have a COE of 89-94.

REACTIVE GLASS: A type of glass that changes color when re-heated. Also called a striking color. Such as Effetre’s transparent red, orange, yellow gold ruby, opal pink and carnelian.

REDUCING ATMOSPHERE: An atmosphere in a kiln, furnace, or flame that is deficient of oxygen. Used intentionally to reduce oxides to their metallic state. In the torch flame an inappropriate reducing atmosphere can cause the glass to discolor.

REDUCTION FRIT: A type of glass made in Germany originally for the glassblowing movement that has a high concentration of metallic oxides. Can be used with, or without the introduction of a reducing flame to create different effects. Available in various colors and sizes from large chips to fine powder.

REGULATOR: Connects to the propane/oxygen gas tanks, controls the flow of gas to the torch, and shows the levels remaining in the tank. Traditionally the oxygen is set to twice the use level of the propane. Propane 5-10, Oxygen 10-20.

REFRACTORY: A substance, usually clay, capable of resisting high temperatures.

RIBBON CANE: A cane created by joining several or more rods of glass together, (overlapping 1 inch), side by side to create a wide flat ribbon of glass. After joining, heat and pull straight out to the desired width. The slower you pull the wider the cane will be.

RIBBON GLASS: Term for glass made from ribbon canes arranged in parallel rows, or geometric patterns. First made in the 1st century, also in Venice called vetro a reticello.

RIGAREE: A raised band or pattern of bands usually made by crimping applied trails with a tool while hot.

ROD: A monochrome length of glass cut from a trail. Rods of glass are used in flameworking. Two or more colors and it becomes a "cane".

ROD FORMING: The technique of winding molten glass around the tip of a narrow metal wire or mandrel coated with kiln wash or bead release which acts as a separating agent. Rod forming is used in flameworking to create beads, pendants, and core form vessels.

ROSE CANE: See cased cane.SAGGING: The process of re-heating a glass object, so that it flows under its own weight into or over a mold or form.

SAND: The most common form of silica used to make glass. For most present day glassmaking, the sand must have a low iron content. Before being added to the batch, it is washed well, heated to remove carbonaceous matter, and then put through a screen to obtain uniform size small grains.

SATAKE GLASS: Beautiful, hand pulled, lead based glass rods for flameworkers and beadmakers from Japan. Satake glass is very soft, and is available in a wide range of unique, vibrant colors. The COE of Satake glass is 113-121.

SCALE: An accidental inclusion of impurities in glass, consisting of corrosion products detached from the metal tools used to stir the batch.

SILICA: Silicon dioxide, a mineral that is one of the essential ingredients of glass.

SINTERING: The process of heating the raw materials that make glass so that they become a coherent mass, but do not melt. See frit.

SMALT, (Smalto, Smalti Italian, made from enamel powder): Colored glass, often ground to use as colorants for glass enamel. Smalti, tiny glass tiles are most frequently seen used in glass mosaics of intricate designs throughout Venice, Italy and Europe.

SNAKE THREAD DECORATION: A type of trail decoration that resembles the sinuous body of a snake.

SODA: Sodium carbonate. Soda (or alternatively potash) is commonly used as the alkali ingredient in glassmaking. It serves as the flux reducing the fusing point of the silica during the melting of the batch.

SODA-LIME GLASS: Historically the most common type of glass. It contains three major ingredients in varying proportions, silica 60-75%, soda 12-18%, and lime 5-12%. Soda-lime glass is relatively light, upon heating remains workable (plastic) through a wide range of temperatures, lending itself to elaborate manipulative techniques. Effetre (formerly Moretti) glass is an example of soda-lime glass.

SOMMERSO, Italian, under: Name for cased beads, most often with gold leaf or silver foil, (sometimes aventurina) underneath.

STONE: An accidental inclusion in glass. Stones are unmelted particles of the batch, pieces of refractory material from the pot, or devitrified crystals.

STRAIN CRACKS, Stress fractures: Fissures in a glass object caused by internal stress resulting from inadequate annealing and/ or thermal shock.

STRINGER: A stringer is a one-color pull of glass. Heat the middle of a ½ length glass rod, (approximately 20 inches long), or the ends of two-1/3 length glass rods, (approximately 13 inches long each). Make a gather dime to nickel sized by balling up the glass, or gently pushing it on to itself. When the whole gather begins to flop, come out of the flame towards you, wait about ten seconds while continuing to turn so as not to allow gravity to pull the hot glass down, and then slowly begin to pull the two ends apart. It is important to pull slowly or the hot glass may drip. As the stringer begins to cool you will want to pull progressively harder to keep the stringer as even end to end as possible. The slower you pull the thicker the stringer will be.

STRIKER: A tool containing a flint used to start a torch flame.

STRIKING: The process of re-heating glass after it has cooled, to develop the color or the opacifying agent, which appears only within a limited range of temperatures.

STUDIO GLASS: A term coined in the 1960’s to describe unique or limited edition glass objects designed and created in a studio instead of a factory. Often created by one artist, although not always.

STUDIO GLASS MOVEMENT: A movement that began in the States during the 1960’s and has spread all over the world. It is best characterized by the proliferation of glass artists who are not affiliated with a factory, instead creating art glass in their own studios.

TANK: (1) A large receptacle constructed in a furnace used to melt the batch. (2) For present day flameworking, an oxygen or propane tank.

TESSARAE (Italian, "small square tablet or block"): A small piece of glass (smalti) used to create intricately designed mosaics.

TOOL: General term that describes any tool used by glassworkers during the creation of a glass object.

TRAIL: A strand of glass used to decorate the surface of a glass object.

TRAILING: The process of applying trails of glass as a decoration on a glass object.

TUNGSTEN CARBIDE NIPPER/CUTTER/DISC CUTTER: A tool with a very strong steel blade used for cutting glass rods and canes. The disc cutter has two tungsten carbide wheels, which can be turned if one area gets dull, and even replaced making them the favorite.

TWISTED CANE, or twist: A twisted cane consists of groups of rods of different colors, which are bundled together, heated and fused, then pulled and twisted. Thus forming a polychrome design that is visible when seen through the length of the cane. A twist is two or more rods of glass overlapped by 1 inch, attached together, heated and finally pulled and twisted. You can combine any rods of basically the same coe together, (such as transparent, opaque, opal, special, alabaster, filigree), but to start with lets just try three, (you will eventually be able to handle larger and larger bundles of glass). So, choose three glass rods with different values, (not all light colors or all dark or you wont see much). Take the first two rods and warm up a 1 inch length at the end of each rod. Don’t get them too hot and floppy or they will be very hard to combine. Connect the two rods together overlapping them 1 inch. Cut one rod off right at the end of the bundle, (it is easiest to cut off the rod held in your most dexterous hand). Put the rod down facing the hot end of the rod away from you. Pick up the third rod and warm up enough to connect to the bundle overlapping the same 1 inch. Remember to keep the bundle warm while you warm the third rod up. When you have connected all three rods heat up the entire bundle end to end and evenly around. When it starts to flop, come out of the flame towards you, wait about ten seconds while continuing to turn so as not to allow gravity to pull the hot glass down. Then slowly begin to pull and twist the two ends apart, (one hand towards you the other away). It is important to pull slowly and twist rapidly to create a nicely twisted cane. As the cane begins to cool you will want to pull progressively harder as you twist to keep the cane as even end to end as possible. The slower you pull the thicker the cane will be.

URANIUM GLASS/VASALINE GLASS: A type of yellowish green glass colored by adding uranium oxide to the batch. Sometimes opalescent or milky, sometimes translucent, or even transparent. Radioactive glass.

WEATHERING: Changes in the surface of a glass object caused by a chemical reaction with the environment. Weathering usually involves the leaching of alkali from the glass by water, leaving behind siliceous products that are laminar, sometimes appearing iridescent.

 

Written and compiled by Kimberley Rosaleen Osibin - Flameworked Glass Beads

© Copyright February 2001