Glassblowing Vocabulary in English — 20 Essential Terms

The blowpipe and the punty are both metal rods, but they do different jobs. The blowpipe is hollow, so the glassblower can collect a gather of molten glass on one end and blow down it to inflate the glass into a bubble. The punty is solid and is attached to the base of a piece once the main shaping is done, allowing the work to be transferred off the blowpipe and held while the rim and opening are finished. In short, you blow through the blowpipe to inflate glass, while the punty is a holding rod used in the later stages.

Annealing is the controlled, slow cooling of a finished glass piece, usually overnight in a special kiln. It is essential because glass that cools too quickly cools unevenly — the outside hardens while the inside is still hot — which locks dangerous internal stresses into the material. These stresses can cause the piece to crack, or even shatter, hours or days later, sometimes seemingly without warning. By holding the glass at a carefully chosen temperature and then lowering it gradually over many hours, annealing relieves these stresses and leaves the piece stable and durable. No serious glass studio works without an annealing kiln.

The gather is the molten glass that a glassblower collects from the furnace on the end of the blowpipe; the word also describes the act of collecting it. Once the artist begins to blow air into that gather, the first small bubble that forms inside it is called the parison. The parison is the starting form from which the final shape is developed through blowing, swinging, and tooling. A glassblower may take several gathers, building up more glass over the parison, before shaping the piece into its finished form.

The glory hole is a small, very hot reheating furnace, separate from the main melting furnace. Its purpose is to keep the glass soft and workable. As a glassblower shapes a piece, the glass constantly loses heat and begins to stiffen, making it impossible to form. By repeatedly inserting the work into the glory hole, the artist reheats the surface and brings the glass back up to working temperature so the shaping can continue. Much of glassblowing is a rhythm of working the glass for a short time, returning it to the glory hole, and working it again.

Batch and cullet are both materials melted to make glass, but they differ in form. Batch is the dry, raw mixture of ingredients — chiefly sand or silica, soda, and lime — carefully weighed out and melted from scratch in the furnace. Cullet is broken or scrap glass, either recycled from previous work or bought ready-made. Adding cullet to a melt helps the batch melt more easily and reduces waste, since broken pieces and trimmings can be reused rather than thrown away. Many studios use a combination of the two.

Soda-lime glass and borosilicate glass have different compositions and uses. Soda-lime is the most common glass, made mainly from silica, soda, and lime; it melts at a relatively low temperature and is easy to work, which makes it the standard choice for most studio glassblowing and everyday glassware. Borosilicate glass contains boron, which gives it a much higher resistance to heat and to sudden temperature changes. This makes it ideal for laboratory equipment and for lampworking, where a torch is used. Borosilicate is harder to melt in a furnace, so the two are generally used in different kinds of glasswork.

Frit, cane, and murrine are three ways of introducing colour and pattern into hot glass. Frit is granules or powder of coloured glass; a hot gather is rolled in it to pick up speckles or fields of colour. Cane is a thin rod of coloured glass, sometimes with an internal pattern, which can be laid alongside other canes to form stripes and designs. Murrine is made by bundling canes together, fusing them, and slicing the bundle crossways so each thin disc reveals a repeated picture, such as a flower or star. All three can be picked up onto a piece and fused in, allowing glassblowers to build extraordinarily intricate decoration.

The jacks and shears are two of the most important hand tools at the bench. The jacks are a large, spring-shaped tool with two smooth blades, used to shape and refine the glass — for example to squeeze in a neck, define a shoulder, or create the line where a piece will later be broken from the pipe. The shears are strong, scissor-like cutters used to trim and cut hot glass while it is still soft, such as removing excess from a rim or cutting a length of cane. Together with the blowpipe, marver, and punty, they form the core toolkit of the glassblower.

Graal and filigrana are two advanced decorative techniques. Graal involves making a coloured glass blank, carving or etching a design into it, and then reheating it and encasing it in clear glass, so the design appears to float within a thick, glossy wall. Filigrana is a Venetian technique that uses canes containing fine threads of white or coloured glass; these are arranged and fused to create delicate striped, netted, or lacy patterns running through the piece. Both techniques have long histories, especially in Italian glassmaking, and require considerable skill, but learning their names helps you recognise the rich variety of effects possible in studio glass.

The most effective approach is to connect the words to the actions they describe. Glassblowing is a sequence of clear steps — gather, parison, shaping with the jacks, reheating in the glory hole, transferring to the punty, and finally annealing — so watching English-language demonstrations and naming each step as it happens is very powerful. Visiting a glass studio or museum and reading the English labels also helps fix the terms in context. Practise the 20 words on this page with Flash Cards on LexFizz, then test yourself with the Matching Pairs exercise to make sure each tool and technique is firmly linked to its meaning.