This illustrated glossary / dictionary is a 'work-in-progress'.  Please check back as we take more pictures,
and continue to edit the definitions.  If there are any terms you'd like us to include or areas
you'd like to see covered, please let us know.


Technically, an amphora is an ancient two-handled jar, but glassblowers use the term to refer to a classical vase form, specifically with a waisted bottom. Amphora


Works made from hot glass need to cool slowly to room temperature, otherwise stresses will develop and they will crack. An annealer (or lehr) is a large oven used to slowly cool the glass from around 900F to room temperature. Typically a 24 hour program is used; if thicker work is made, then a longer program is required. Annealer


Aventurine is a special glass made with flecks of copper. It is very expensive and adds a bit of sparkle to Venetian style work. We use aventurine in our Creeper and Perfume Bottle series of work. Aventurine


Hourglass shaped connecting piece commonly seen in venetian style goblets. The avolio serves as not only a visual element, but also provides a thin spot which makes it easier to use the fork to load the goblet into the annealer. Avolio


Batch is the raw materials that are melted into glass. The process of melting batch is called charging and is quite time-consuming; our furnace requires about 9 hours to cook the batch until it is relatively bubble-free. Batch


A blank is a small hollow glass cylinder made using a specific color technique. Several blanks can be made from one large bubble, then each blank can be used to make a single piece. The white striped blank is used for making mezzo-filigree. Blank


Blocks are typically made of cherrywood and are used to shape, cool and center the glass. They are used early in the process of making a piece, usually soon after the gather is made. There are special shaped blocks for making specific shaped work; round blocks are used to make round paperweights and large marbles. Block

Body Wrap

A body wrap is a single thread of glass that is applied to the outside of a vessel. It is very difficult to put one of these on and have it line up properly. Body Wrap


In additional to being something that you use for soup or cereal, bowl refers to the top part of a goblet, the part that you drink from. There are many different shapes for bowls, used for different kinds of drinks. Bowl

Color Bar

Most glass color come in the form of bar. The major manufacturers of glass color bar are Reichenbach, Kugler, Zimmerman and Gaffer. The process of making these involves adding metal oxides and other toxic ingredients to crucibles of molten glass, and then pulling the glass out and rolling it into bars. Color Bar


Copper (as well as silver and gold) is compatible with glass; in other words, it expands at about the same rate as glass. So, copper wire, flecks, sheets or pipes can be incorporated into glass forms. Copper

Core Drill

Cutting holes in glass is a challenging, expensive proposition. This is a water fed core-drill bit. Water feeds through the center of the bit and cools and lubricates the bit as it cuts. There are many different size bits that can be threaded into this water feed system. This is an indespensible tool for many of our commissioned projects. Core Drill


There are a lot of different crimps that put texture into glass. Seen here are specialized dragon-wing crimps, leaf crimps, waffle crimps and straight crimps. Typically, a hot bit is brought right out of the furnace, dropped on the piece, cut off with shears and then crimped right away before the bit cools. Crimp

Diamond Shears

Diamond shears are typically made with two blade surfaces, the outermost is rounded and used to hold a pipe. The inner surface is sharp and designed to cut the glass to a point. Diamond shears are used when dropping a solid foot onto a vessel, pulling the end of a bubble to stretch it out or any time that cutting the glass to a point is preferable to cutting it to a seam. Different size and configurations of diamond shears are available for different size and types of work. Venetian-style work requires small, thin diamond shears that are very sharp and wick less of the heat from the piece. Diamond Shears


The Digitry is the standard annealer and/or furnace controller used in modern glass studios. It controls up to five seperate annealers and is extremely easy to program and control. Digitry

Exact Torch

The Exact torch is the standard high-pressure torch used in glassblowing to heat specific parts of a work-in-progress. It is a modular system with interchangable heads that go up to about 400,000 BTUs. Exact Torch


The fork is a long metal rod with a forked end on it, used to load work into either a garage or annealer. The fork is typically used when making goblets and other Venetian-style work. Fork


A gas-fired oven used when making complicated work made from many parts. The parts are kept warm in the garage until needed. For example, when making Venetian goblets, the stems and bowls are made first, and then stored in the garage. The foot is made, and then the stem is brought from the garage and attached. Finally, the bowl is brought and attached to the top of the goblet. The right side (cold side) of the garage is kept around annealing temperature (900 F), the left side is usually around 1050 F. Garage


A gloryhole is a gas-fired furnace used to reheat work in progress; glass can only be manipulated when it is hot enough to be pliable. The doors on the gloryhole are opened to accomodate larger work. Gloryhole

Hot Plate

Electric and gas hot plates have many uses in a hot shop other than cooking. They are used most frequently to preheat bits of color or murrini so that the color does not crack upon contact with the work-in-progress. Hot Plate


Incalmo is the advanced technique of joining two glass bubbles of different color together. Typically, one bubble is opened into a cup shape, and then attached to a punty, and the other is opened into a cylinder on the end of the pipe. The cup is then joined on the cylinder to make a two color piece. Incalmo


Jacks, Italian term: pucella, are the most versatile tool in glassblowing. They are used for shaping the glass, selectively cooling the glass and putting creases (jack-lines or neck-lines) in the neck of vessels where they are to break for the transfer. Jacks are made in a variety of sizes and with different blade profiles for different types of work. Round jacks are used specifically for shaping avolios and other operations where a rounded contour is desirable. Jacks

Kevlar Mitts

The kevlar mitts are used when loading work into the annealer. The assistant typically wears the mitts, preheats them with heat from the gloryhole or furnace. Then the piece is broken off the end of the punty into the mitts and loaded into the annealer. Kevlar Mitts

Knock Off Table

The knock off table is an essential piece of hot shop equipment for making production-line work. It is covered with a woven silica fabric that can stand the heat of a freshly made piece and will not wick enough heat from the piece to cause a check. A piece can be knocked off onto the table, and then a torch can be used on the punty spot to soften any sharp edges before the piece is placed into the annealer. Knock Off Table


A decorative element used in goblet stems; the knop is a round ball either with or without optic ribs. Knop


The marver is a metal table used to shape, chill and center the piece. Marvering at different angles is a tricky but necesssary skill for glassblowers to master. Marver


A disk shaped connecting bit used in the construction of goblets. Used similarly to an avolio. Merese

Optic Mold

Optic molds are used to add ribs or indentations to a bubble or solid mass. Optic molds are made from either brass or aluminum and are available in many different configurations. Open-bottom, ribbed molds are typically used for doing cane pickups, close-bottom ribbed molds are used to add either a straight optic pattern or an "optic twist". Pineapple molds create a unique diamond effect on the bubble, similar to the texture on a pineapple. Optic Mold


Paddles are used to flatten the bottom of vessels. A metal paddle (or tagliol) is indispensible for sculpting solid glass into figures. Wooden paddles are also used as heatshields to protect the arms of the gaffer. Paddle

Pi Divider

A Pi Divider is a mechanical calculator that determines the size of a post needed to pick up a number of canes. The canes are layed out on the plate and then measured with the straight arms of the Pi Divider. The curved end will indicate the size of the post. Pi Divider

Pipe Cooler

As they are used, heat travels up glassblowing pipes and punties. The pipe cooler sprays water onto the pipe to cool it. It is important to keep the pipe turning when using the pipe cooler or the pipe could warp. Pipes should be cooled from the cool part first and then up towards the moil. Pipe Cooler


A prunt is an applied bit of hot glass that is stamped. Prunts come in a bunch of different shapes and sizes. Prunt


Reticello is one of the most time consuming and technical of Venetian color techniques. To create the reticello pattern, two twisted cane cups are fused together. The cups must be twisted in opposite directions, and the low spots between the canes act to trap air, creating the little air bubbles inside each diamond. You can see a step-by-step illustration of Maestro Elio Quarisa making a reticello goblet. Reticello

Rolling Yoke

A rolling yoke is a necessity when making larger scale or heavier pieces. The gaffer can move the yoke towards the gloryhole as needed to help manage the weight of the piece. Rolling Yoke


A roundel is a glass platter that starts life as a glass bubble, which is then heated up and spun open. In the olden-days, window glass was made from roundels. Roundel

Safety System

Modern studios add safety system to the combustion train of each piece of equipment. The safety system shuts off the equipment if any sort of fault is detected. There are shutoff valves that activate if the gas pressure is too low, too high, or if the flame goes out. Safety System

Silver Suit

These very attractive suits allow loading of hot work into a hot annealer without getting burned. They are also helpful when working on the furnace. Silver Suit


Soffietta is an Italian term meaning: little puffer. It is a cone on the end of a small pipe that is used to inflate a vessel after its been transferred to the punty. The bent soffieta allows the gaffer to inflate the vessel without an assistant. Soffieta


The stem connects the foot of a goblet to the bowl. This is a traditional chicken-leg shaped stem. Most of the creativity in Venetian goblets is expressed in the stem; animals, flowers and fancy bitwork are common. Stem


The tazza is one of the hardest shapes to make well. It is a low bowl form and is used for champagne or possibly desert. It is extremely difficult to get smoothly contoured sides. Tazza


Tweezer are used to pull, squeeze and shape hot glass, different sizes are available for different scale work. Tweezers


This is the brain that controls the safety system. The Veri-Flame system is the standard used at most glass studios, though there are other manufacturers. Veri-Flames are relatively simple and economical. Veri-Flame

Wet Saw

A tile-cutting wet saw cuts through glass just as easily. The diamond impregnated blade is water cooled. Wet Saw