Glass Art Dictionary,
Terms, and Phrases
Art Glass Working Terms & Phrases
The process of gradual cooling of the outside and the inside of the molten glass to assure that the glass won’t cool to fast causing cracks or breaks.
The glassworker that works directly for the Gaffer. In some situations, there may be several assistants depending on the size of the project.
A molten glass object ready for the further creation of the Art Glass piece.
The forming tool used for the shaping of the molten glass. The “Block” is usually made of cherry
wood and is “wet” while used with the hot glass.
Blocker – The glass worker that
actually “blows” the first bubble through the blowpipe and then subsequently transfers that blow-pipe to the Gaffer.
Blower – The glass worker that
blows the air through the blowpipe (within the mold or freehanded). Upon occasion, the gaffer might do the blowing of the air themselves to have more
Blowpipe – A steel pipe with a air
passage way throughout it’s entire length. One end has the mouthpiece and the other has the larger built up area for the molten glass to gather and blow
the bubble on.
Bubbles – Gases in the molten
glass while melting in the “pit” get trapped. The hotter the molten glass along with the purity of the quality of the glass can greatly diminish this
problem. While gathering the molten glass those bubbles will be transmitted to the actual art piece itself. Some artists do like the bubble effect and
use them in their works by forcing a bubble. Installing bubbles may me made with a sharp object being punctured into the molten glass or countless other
Burner – Runs the air and gas
mixture control for lampworking.
Burn-mark - The residue left from
the usage of a newspaper ash in the assistance of shaping of the molten glass.
Button – A small usually clear
amount of molten glass placed on the “working end” of the art piece project to assure proper connection of the glass to the pipe to avoid dropping
damage. A button may also be used as a part to the actual glass project to enhance a particular art piece.
Caliper – Tongs that help create
and control the molten glass piece.
Cane – A cross section of glass
made by pulling and stretching molten glass from both ends. Several color pattern and designs can be created. Whatever design is used along with the
detail will continue to hold the precise shape, scale all the way down to an invisible dimension.
Carving – Removing excess molten
glass off of the working piece.
Casing – Placing an additional
layer of glass over and existing layer of another color.
Casting – The process of pouring
molten glass into a form designed to receive that glass. After the glass has cooled, that mold or the removing of the sand will then reflect the filled
Chill-mark - Any time and
instrument is used on hot glass there's a potential for it to leave a cooled surface that refracts light differently.
Chord - These are lines of clear
glass that have a slightly different expansion coefficient enhance refract light at different rates.
Chunked – A glass piece that has
been badly damaged.
Cold Working - Any work, grinding,
surfacing, and drilling that is done on the glass that has been finished after the annealing process is completed. Working without heat.
Collar – A ring that is
used to hold the cane glass into place on a working piece.
Color - 99% of the color used
comes from Germany or Bulgaria. The transparent colors are nearly all black until blown out in a piece and come shaped like a small rolling pin. The
opaque colors are most often the same color as they started before melting.
Contemporary Glass – Artist
designed glass exclusively for their own creative use.
Cord – Visible deficiencies in the
glass quality product itself from streaking to slight color haziness.
Cullet – Mixing slag, scrap or
other extra glass materials into a pit to assist in the melting process. This also reduces the quality of the glass product itself.
Cutting – Grinding any pattern
into the glass by using a consistent speed rotating wheel coated with either cloth, diamond dust or an abrasive.
Cut-to-Clear – Showing the under
layers of the glass by cutting however many layers needed to complete the desired effect in the glass.
Double Overlay – Coating a glass
Embossed – Raised or
lowered text or design on any surface of glass.
Etching Decoration – Using acid to
etch the glass. Strengthen or get an chemical reaction or effect with the glass surface.
Finisher – The glass worker (generally the Gaffer) that puts the finishing touches on the glass
before it goes into the Annealing Oven.
Flashing – Quickly placing the working glass into the Glory Hole to reheat the entire piece to
assure that the glass will be pliable and keeping it safe from cracking.
Fluted – The vertical lines,
grooves or designs in the glass.
Founding – Heating the glass to a proper usable temperature.
Fritt - Clear or opaque color that is crushed and graded to specific sizes.
Gaffer - The senior member of the
blowing team in charge of the entire production of a project
Gather – Placing molten glass on
the end of the blowpipe or pipe for the further development of that glass project.
Gathering - obtaining a layer of
clear glass over a subsequent layer of glass.
Gilding – Using leaf (golf or
silver), painting or effects to add interest to the surface of the glass.
Glory Hole – The opening of the
furnace used to keep the glass hot and workable. Several different sizes may be attached to a large furnace or you might have only one size on a small
one that rotate open and closed depending on were the glass project is at. The cylinder is usually heated up to 2300 degrees.
Hand Blown – A glass project is
handmade and was not assisted by machinery.
Iridescence – Spraying a shiny
metallic finish onto hot glass.
Jack - A tool shaped like huge
tweezers used to manipulate hot glass. Making a Jack line is often the line that will be used to separate the glass work from the blowpipe or pipe with
the droplets of water.
Knurling – A glass band or bead
wrapped around a larger project.
Lear - A gigantic oven that is
computer-controlled to relieve stress during the annealing process.
Marver – A flat steel plate that’s
used for the picking up color chips or the shaping of molten glass on the end of a blowpipe or pipe with a rolling action. A Marver can also help in the
uneven cooling of the glass for a desired effect.
Mould Blown – An open ended
cylindrical designed to create effects or grooves in the molten glass by blowing into the blowpipe while in the mould vertically.
Murrini – A cross cut piece of
glass (with a design or color pattern) used in the creation of a larger glass works.
Necking – Reducing an end of a
blown glass to form a bottle neck.
Overlay – A thin layer of clear or
colored glass is folded, formed or coated over another.
Overshot Glass – Rolled molten
glass is covered with splinters covering the surface as a final completed surface.
Parison – The first small bubble
at the end of a blowpipe.
Pattern Mould – Pre-shaped
patterned on the molten glass before the bubble is blown.
Pegging – Placing a Parison (small
air bubble) into a gathering pit.
Pick-up Decoration – Picking up
color from a Marver before blowing the glass out.
Polishing – Buffing the glass cuts
or grindings to a bright clear luster.
Pot – A holding area for molten
glass where the glass is continually kept at a designated heat for gathering.
Power – Is the ground glass that
is put into the Pot for melting the final molten glass that will be used by the hot glass workers.
Punty - Is the hot glass or
gathering that is placed on the receiving pipe for transferring the glass work that is currently connected to the blowpipe. The technique used to change
the end of the glass that is being worked on.
Rag – Tick layers of wet
newspapers folded to provide a cool safe pad for the glassworker to shape the hot molten glass.
Ringer – the glass worker that
applies the ring for glass to the larger piece.
Rondelle – A flat blown glass that
was spun hot.
Sandblasting – A method used to
remove layers of glass. A cloudy dull finish will result with every layer removed. Some artist use the sandblasting process to remove enough glass to
actually go through the glass for different effects.
Satin Glass – A acid matt finish
Sawing - Cutting glass with a
rotating wheel with a blade usually diamond tipped.
Scavo – A process where a
corrosive chemical is added to the surface of a hot glass while cooling to give the surface a rougher matt finish.
Sculpting – Handmade free forming
solid glass works designed while in molten glass form.
Shard – Glass fragments usually
colored of which would be rolled or melted into a working piece for the additions of colors of textures is not melted all of the way. Different colors
melt at different temperatures lending creative textures with variation.
Shears – Glassmakers scissors that
are used for the cutting, trimming and shaping of hot glass. Usually very primitive in design with heavy gage steel.
Silesia – The main ingredient of
glass used for art glass.
Silveria – Is a type of art glass
with incased silver foil.
Slumped – Flat glass that is
melted to take the shape of the form designed to sink into taking the actual shape of that form.
Sodium Flare – The bright light
that is given off of the reaction of oxygen rich flame and the sodium of the glass in a kiln. Didymium glass in the glasses to avoid serious damage to
the vision of one’s eyes. Usually, Flame-workers Lamp-workers are at the primary concern here.
Soliflore – A French term for a
vase with a bulbous body and a long drawn out neck for a single flower.
Spatter Glass – The glass with
flecks of contrasting color rolled into it.
Sputtering – A metal coating
process for the glasses surface.
Stretch Glass – A cracked
iridescence on the surface.
Strike – The change in the color
of the surface after the glass piece is reheated with intense heat on that surface.
Stringer - Like cane but applied
from a molten glob of color over the surface of hot glass.
Teardrop – A glass shape that is
usually blown from above and allows a consistent growth of a glass blown into it.
Thermal Shock – The cause
by a sudden shift of temperature hot or cold causing the glass to break, crack or shatter.
Thermocouple – Bimetal probe that
measures the kiln’s temperature.
Tongs – Glassmakers tool for
picking up, transferring and applying water to the Punty to remove the glass piece from
the pipe of blowpipe.
Virtual Production Replications –
is the remaking and replacement of an unattainable (non-art)
original "production" glass piece with an as close as possible custom made glass piece for repair, recovery or restoration for historic purposes, etc.
Wetting Off – The
separation line for the glass work from the blowpipe or pipe uses cold water to fracture control the break and separation.
Wrap – A term used for the
heavy outside bead of glass that is used generally for creative style sometimes used as a contrasting color from a vessel.
Yoke – The weight support for the
glassworker while in the glory hole while being flashed.