| Abrasive
etched |
Glass
that has had the surface roughened by an abrasive. This usually results
in a "whiter" color. If the glass was flashed ( see
definition), the etched area may be a different color.
|
| Acid
etched |
Glass
that has had a layer
eaten away by hydrofluoric acid.
This leaves a matte finish and
usually a lighter color.
|
| Annealed |
Glass
that has been cooled slowly,
resulting in a soft glass that
is easy to cut. Opposite
of "Tempered." |
| Antique |
Glass
made by the “antique”
method, namely by an artisan
blowing a glass bubble that is
formed into a cylinder, that is cooled,
cut open, and then flattened in
a reheat oven.
This glass is
characterized by variations in
thickness that give the glass a
gradient in color across each
sheet. It usually also has some
small air bubbles and/or
variations in the refractive
index that produce slight
prismatic effects. |
| Architectural |
Glass
designed to become part of a
building's structure. This
term is used when the architect
specifies the glass as part of
the architectural design. |
| Art |
A
generic category that covers all
artistic uses of glass as
contrasted with functional use.
Typical art glass types are
stained glass, carved glass,
fused glass, lamp-worked glass. |
| Artique |
An
imitation of antique glass made
by Spectrum Glass Company.
The fine lines from a change of
density in antique glass are
molded into the surface of this
glass giving a similar effect
in a machine-rolled glass at
lower cost than true antique
blown glass. |
| Backing |
A
thin piece of glass used to hold
together broken fragments of old
glass by adhering to them
(usually with silicone or
epoxy).
|
| Back-lighting |
A
method of using artificial light
to illuminate stained glass not
illuminated by sunlight.
|
| Baroque |
An
artistic style of stained glass
characterized by the use of
curved lines and extravagant
ornamentation.
|
| Bent |
Glass
that has been bent by heating
and , usually, forming it over a
curved mold.
|
| Beveled |
Glass
that has the edge cut off
at an angle. This bends the
light and produces a prismatic
effect.
The bevel is made by
grinding off the edge of flat
glass. Straight-edged
bevels can be made by multiple
machine grinding steps while
curved edge bevels must be
hand-made.
|
| Blown |
Glass
made from blowing a glass bubble
on the end of a hollow tube.
An artisan may then shape
it by spinning, rolling and
pinching with iron tools to make
a vase, bottle, glass or other
object.
Alternatively, the bubble
may be placed into a hollow mold
and further blown until it
expands into all of the details
of the mold. |
| Border |
A
band of glass that surrounds the
main work in a window. It's
purpose is to frame but also to
allow removal of a non-essential
area to adjust the fit of the
stained glass to the window.
It is often made of strips,
geometric, or plant shapes.
|
| Bottle |
Sheet
glass that is cut from the four
sides of a glass bottle that was
blown into a square mold.
It has been replaced by the
cylinder-blowing method
described under
"Antique."
|
| Carved |
Glass
with the appearance of a
three-dimensional sculpture
imprisoned within the glass.
This is achieved by
etching the glass to varying
depths. |
| Cast |
Glass
made by pouring molten glass
into a mold. |
| Cathedral |
Transparent
glass of uniform thickness made
by squeezing molten glass
between rollers.
The color is uniform
across the piece of glass (no
color gradient). Usually one
roller is smooth and the other
textured, which gives texture to
the glass.
(See “Hammered” below
for one of the more popular
textures). |
| Copper-foiled |
Copper-foil
is a method for making 2 or
3-dimensional objects from small
pieces of colored glass.
Very thin strips of
copper foil are wrapped around
the edges of each piece of
glass.
The pieces are positioned
into the desired shape or design
and then soldered together.
The copper foil is
completely hidden underneath the
solder, which is usually
blackened by application of a
patina-forming chemical.
Stained glass lamps of
all shapes are made by this
method. |
| Crackle |
Glass
made by dipping a molten
cylinder into water. The
exterior of the cylinder cracks
but the molten interior holds it
together. The cylinder is
sliced down the side and
flattened. There are now
imitation crackle textures
rolled into glass. |
| Crown |
Glass
that is rotated as it is blown,
thereby creating a disk shape
with a knob, or crown, in the
center.
Same as Roundel.
|
| Cut |
Sculptural
glass (three-dimensional, like a
vase or goblet) that has designs
cut into the glass with a copper
wheel. |
| Curious |
Glass
that did not meet the
manufacturer's specifications
(in other words,
"rejects").
Mostly this glass is very
unusual, unpredictable,
sometimes beautiful and
sometimes ugly. |
| Cylinder
|
Most
common type of blown glass. The
glass bubble is blown into a
cylinder, the ends cut off, the
cylinder split along its length,
and then unrolled into a flat
sheet.
|
| Dalle
de Verre |
“Slab
of glass” (translation from
the French) is a
cast chunk of glass
approximately 1” x 10”
x
8” that is used to make
“faceted” glass windows (see
“Faceted”). |
| Dichroic |
Glass
which has a thin metal film
vaporized onto its surface. The
glass transmits one color and
reflects a different color. Each
manufacturer offers about a
dozen different color
combinations. |
| Drapery |
Glass
with varying thickness and
irregular ripples. It is
made by pushing a hot sheet of
glass across a tabletop into
folds resembling fabric drapery.
|
| Enameled |
Glass
design made by melting enamels
on the surface of the glass.
|
| Encapsulated |
Glass
which has been sealed inside a
"sandwich" of two
sheets of clear glass. |
| Epoxy-laminated |
Art glass
laminated to a plate
glass substrate by clear epoxy.
|
| Etched |
Glass
with some of the surface removed
by either a chemical or
sandblast process.
The result is that the
glass is slightly thinner in the
etched region and has a diffused
reflective surface, thereby
appearing whiter in color. |
| Faceted |
Slab
glass that has been chipped on
the edges to cause thin flakes
of glass to break off the flat
surfaces.
Pieces of this type of
glass are set into an
epoxy-concrete mixture to
produce large architectural
window-walls. The fractured
edges ("facets") cause
the light to bend and refract
(break into a rainbow of
colors). |
| Favrile |
Type
of glass produced by Louis
Comfort Tiffany that is
opalescent with a coppery
metallic coating. Note:
Starting in
1892, Tiffany called his
glassware "Fabrile",
supposedly, derived from the old
English, meaning
"hand-made".
"Fabrile" evolved into
"Favrile", which he
trademarked on November 13,
1894. He used this word to apply
to all of his glass, enamel, and
pottery.) |
| Fired |
Heated
to a critical temperature in a
kiln.
The temperature depends
on the glass and the desired
effect. Painting becomes part of
the glass about 1200 degrees F.
Glass will slump or fuse
(see definitions) at higher
temperatures. |
| Flashed |
The
glass has a thin coating of a
second color of glass processed
onto the base glass. For
example, most antique reds are
made of clear glass with a very
thin layer of intense red glass. |
| Flat |
Glass
art that has minimal thickness.
The glass has NOT been
worked into a three dimensional
shape by being bent or fused or
otherwise assembled or
distorted.
|
| Float |
Glass
that is made by floating molten
glass on a bed of mercury.
This makes an extremely
smooth and flat surface. |
| Fluted |
Glass
that has evenly spaced flutes
running parallel to each other. |
| Fused |
Two
or more pieces of glass that
have been melted together to
form one piece. |
| Globs |
Non-uniform
round or oval smooth
"puddles" of glass
with one flat rough side formed
by dripping glass onto a table. |
| Glue-chip |
Glass
that is covered with an animal
glue and then dried in an oven.
The glue shrinks and pulls chips
out of the glass surface leaving
a delicate, random, feathery,
fern-like texture. This process
can be repeated for a denser
"double chip"
appearance. |
| Grisaille |
Black
or brown fusible paint used for
shading on glass. Grisaille
glass is glass that has been
painted and fired. |
| Hammered |
Glass
textured by indentations which
resemble a surface that has been
beaten with a ball-peen hammer. |
| Hot |
Glass
that has been worked by a hot
process such as fusing, firing,
blowing or lamp-working. |
| Inlaid |
A
type of laminated glass where the art glass is laminated to a plate
glass substrate by epoxy. |
| Insulating |
Two
pieces of glass that have been
sealed together at the edges.
The edge strip usually contains
a desiccant to prevent moisture
on the interior glass surfaces.
The space between the glasses
may be filled with argon gas. |
| Iridescent |
Glass
on which a very thin coating of
metal has been applied.
This thin coating reflects light
from the upper and lower
surfaces of the metal.
These reflected light waves
interfere with each other and
produce a rainbow effect similar
to that produced by a thin film
of oil on water. |
| Jewel |
Glass
that is cast into molds with
jewel-like facets and then
polished to a smooth brilliance. |
| Laminated |
A
sandwich of two pieces of glass
with a plastic-like material
between them. In this type of
safety glass, it is difficult to
penetrate the glass even if both
layers of glass break.
Automobile windshields are made
by this process. |
| Lamp-worked |
Art
glass that is made by heating
with a torch and then
"worked" in order to
bend or fuse or shape the glass. |
| Leaded |
Type
of art glass that is made by
connecting pieces of glass with
a lead channel and soldering the
intersections of the lead
channel.
This has been the method of
making church windows since the
earliest times. Lead has the advantage of being
strong enough to support the
glass but flexible enough to
withstand the thermal expansion
stresses from the glass and the
window encasement.
|
| Liturgical |
Glass
designed for a prayer or worship
space. |
| Medallions |
A
series of stained glass panels
that have been arranged within a
larger window in a narrative
sequence. |
| Mosaic |
Opalescent
glass that has been sliced into
small pieces (smalti) for
assembly into designs that are
cemented into building walls,
floors or other surfaces.
Mosaic pieces may also be
composed of natural stone or
ceramics. |
| Mottled |
Glass
that has variation in coloration
in the form of small spots, some
of which run together. |
| Obscure |
Clear
glass through which images
cannot be can be seen because
the light waves are bent by the
texture on the glass surfaces.
Obscure glass is used where
light is desired but visibility
is not, for example, in a
bathroom. |
| Opak |
Glass
which has a thin coating of
white on one side.
This makes it behave
somewhat like opalescent glass,
but gives a more delicate effect
which transmits more light. |
| Opalescent |
Glass
containing some white pigment.
The glass transmits some of the
light striking it and reflects
other light. Most of the glass
used in the "Tiffany"
style windows and lamps is
opalescent glass.
|
| Painted |
Glass
with designs painted onto it and
then fired so that the paint
becomes part of the glass.
|
| Plate |
Thick,
clear, smooth commercial glass.
See "Float". |
| Plated |
Multiple
layers of glass used together to
achieve a color not available as
a single piece of glass.
Tiffany often plated two or
three pieces of glass to obtain
the realistic shadings of images
in his designs. |
| Reeded |
Glass
with uniform parallel ridges.
Any dimension given
specifies the spacing, for
example, "1/2 inch Reeded
glass." |
| Reinforced |
Leaded
glass
that has been strengthened by
the use of iron. Common methods
are:
- a)
Narrow
strips within the lead
channel.
- b)
Flat
bars soldered to the back.
- c)
Round
bars into the casement tied
to the window with wires soldered
into the lead joints.
|
| Residential |
Art
glass designed for residences.
|
| Restoration |
Clear
glass that is manufactured to
resemble glass made in the 18th
and 19th centuries.
This glass has some slight
variation in thickness that
causes some distortion. |
| Ripple |
Glass
with a ripple texture rolled
into it while still molten.
Various widths exist from fine
(spaghetti ripple) to wide. |
| Roundel |
Glass
that is rotated as it is blown,
thereby creating a disk shape
with a thicker center and a
cut-off from the punti (iron
glass-working rod). |
| Safety |
Glass
with reduced hazard of injury when it breaks, and therefore
specified by building codes for
hazardous areas. The two main
types are Tempered and
Laminated. (see definitions). |
| Seedy |
Glass
that contains small bubbles or
“seeds”. |
| Slab |
Glass
poured into a mold to make
small slabs of glass. See
"Dalle de verre." |
| Smalti |
Molten
opalescent glass poured into
pizza shape and then hand cut
into small uneven squares (tesserae)
used for assembling mosaics.
|
| Stained |
Colored
glass assembled into designs.
The color comes from the
addition of metallic oxides
during the process of melting
the glass ingredients. The name
comes from the silver nitrate
that was used in the Middle Ages
to "stain" clear glass
yellow or orange when fired.
|
| Tempered |
Glass
that has been heat treated to
make it very hard and brittle.
When the surface is broken
anywhere, the entire piece of
glass shatters into tiny pieces
without sharp edges. The rear windows of
automobiles are made of tempered
glass.
|
| Tessera |
A
small piece (normally square) of
glass or marble used to make
mosaics. (plural
= tesserae)
|
| Tiffany |
Used
to describe either:
|
| Transparent |
Glass
through which light passes
freely.
Glass through which objects on
the other side of the glass can
be seen.
|
| Vaseline |
Glass
that is the color of petroleum
jelly, emits slight
radioactivity, and glows neon
green under ultraviolet light.
|
| Vision-obscuring |
See
Obscure. Opposite of
transparent. |
