abrasion:  the process of grinding away the top surface of a piece of flashed glass.  A diamond coated burr or grinding wheel may be used to accomplish this.

antique glass:  sheet glass made by the centuries old method of mouth blowing.  The glass is blown into cylinders.  The closed end of the cylinder is cut off and the side cut to flatten into a sheet.

breaking the score:  separating a piece of glass into planned sections along a marked and scored line.

cartoon/drawing:  the line drawing for a work of glass with all cut lines shown. Individual pieces may be numbered and color shadings indicated. A second copy is cut for pattern pieces.

cathedral glass:  transparent, colored glass, machine made to uniform 1/8 thickness and either smooth or with a choice of textures.

composition:  the overall design of a finished piece with proper color balance and line design.

copper foiled glass:  glass that is wrapped with adhesive-backed copper strips and completely soldered front and back to create a flat or dimensional object.

cut line:  the thin line drawn on glass to score with the glasscutter.

dalle de verre:  a thick slab of stained glass (8"x ll"x 1") for use with epoxy or cement.  Can be chipped and faceted for a jewel-like effect using the copper foil technique.

etching:  method of removing one layer of color from flashed glass in a hydrofluoric acid bath.  The glass to be etched is exposed via cutting a stencil from a completely covered piece of glass.  Available softer etching creams "cloud" the exposed surface on cathedral glass but will not work on flashed glass.  (Hydrofluoric acid attacks and dissolves glass and is very dangerous to handle.)

flashed glass:  one sheet of glass made of two layers of color.  Any color can be flashed on top of another, for example: blue on clear, red on yellow, red on green, etc.  This glass enjoys heavy use for etching to avoid cutting distracting lines in a design, or for the particular shade or variations of color produced when using mouth blown flashed glass.

fusing:  the technique of controlled melting of combinations of glass in layers using a kiln.  This requires knowledge of the individual pieces of glass as to the coefficient of expansion (C.O.E.) rate so that compatible glass is used to avoid different heating and cooling movement.  Glass that does not have the same C.O.E. rate will shatter in the kiln or within hours during cooling due to internal stress.  Required high temperatures can range from 1550° to 1750°.

enamels:  soft powdered colored glass that is mixed with a medium and painted onto the glass with a brush.  When the medium is dry, the glass is placed in a kiln for firing to temperatures ranging from 1250° to 1350°.

glass bending:  the shaping of glass over (draping) or into (sagging) a mold by placing the flat glass onto the mold and firing in a kiln.  The temperature required for bending glass are not as high as fusing, usually around 1350° to 1400°.

glass globs or nuggets:  thick, rounded pieces of glass, usually cathedral colors available in plain or iridescent.  Size ranges from 1/2" to 1" and are free-form rounded shapes.

glass jewels:  these cathedral or opalescent glass have been pressed into steel molds and then polished for consistent shapes and sizes.  Facetted round, navettes and square shapes; smooth ovals and rounds, raised swirls and "iceberg" shapes are just a few of the types of jewels available.

glass thickness:  this can vary from 3/16th of an inch on the thinnest edge of mouthblown antique, up to almost 1/2" on the opposite side of the same sheet.  The sheet of antique glass may not be completely flat for cutting and should have a towel or soft cushion material placed under it for cutting.  Machine made glass is consistently 1/8" but can have a soft pebble or a high, rough ripple or folded drape-textured effect to increase thickness.

granite-back glass:  a type of texture with one smooth side and the opposite slightly rough.

grozzing:  snipping away the excess small points of glass, along the scored edge of glass, that did not break away cleanly.  Use the curved, small fine tooth portion of the breaker/grozers to wear the glass down.

hammered glass:  usually this texture is applied to cathedral glass but can also be found on opalescent.  It takes the shape of small round marks resembling indents in metal made with a ball peen hammer.  These can be consistently placed in rows in round, slightly elongated and irregular shapes depending on the glass manufacturer.

hydrofluoric acid:  the only liquid material that will dissolve silica — the main ingredient in glass.  The length of exposure to this corrosive acid will determine how far the acid will eat into the glass.

joint:  in the lead came technique, the point where lead lines meet one another.  The joints usually butt one against the other.

kiln:  a chamber made of firebrick in which to bend or fuse glass.  Size ranges from small tabletop units to 3' x 4' bed, floor models.  They can be electric or gas heated, use pyrometers to measure temperature and have shut-off controls tripped by ceramic "cones" or computerized timers.

knapping:  the process of faceting slab "dalle" glass by chipping at the edges to flake off rainbow-shaped pieces with the slab glass hammer.

lead came:  extruded pure lead that is milled to specific dimensions as either "U" or "H" shaped strips, then cut and formed to accept and hold the stained glass shape.  It's available in spools or precut lengths of about 6 feet.

leaded glass:  glass held together by lead carries, soldered at all abutting joints.

leading:  assembling a work of stained glass where lead came is holding the material together.

mold:  high temperature fired shapes into which glass can be draped over, or sagged into.  These can be commercially made terra cotta or stainless steel forms.  Free-shaped forms can be created with resin impregnated refractory fabric, or hand carved from soft firebrick.

mold release:  a dry powder mixed with water to a thin consistency that is brushed onto the surface of the mold to prevent the glass from sticking at a high temperature.  It is also used on kiln shelves.

opalescent glass:  non-transparent glass where the colors are presented by reflected light.

oxidation:  the dull, tough, outer covering on lead came that occurs with exposure to air and must be removed with a wire brush prior to soldering.  It's the dull finish on copper foil that was not soldered promptly.  This can be removed by light rubbing with #000 or extra fine steel wool.

pattern:  the paper template which is placed on the glass surface for tracing prior to cutting.

pontil:  the blowpipe used in gathering and blowing molten glass.

pot glass:  glass that is of one solid color, no texture and extremely opaque with no light transmitted.  Two examples are solid, dense white and black.

pot metal:  the medieval name for the molten glass batch.  It was heated in a large crucible and metallic oxides were added for color.

reamies:  sheets of antique glass with faint, delicate streaks of color swept through it.

reinforcing bars:  galvanized steel rods used to span a lead or copper foil window to prevent it from bowing.

resist material:  used to protect areas of glass during acid etching or sandblasting procedures.

rolled edges:  The smooth but uneven wavy sides of raw sheet glass from the lehr.  This must be cut away to gain a straight side. Few manufacturers leave these edges untrimmed, while others, producing larger sheets, cut them for recycling.

sandblasting:  another method of removing glass from a specific area where a design within the panel.

seedy glass:  cathedral glass that has small elongated air bubbles trapped inside.

score:  the line imposed by a glass cutting wheel upon the surface of the glass.  This "fracture line" weakens the surface tension of the glass and allows it to be broken in a controlled manner.

semi-antique glass or new antique:  machine made glass with little surface marking or texture but with brilliant, jewel-like tones.

solder bead:  the solder build up on copper foil, to a rounded shape, for strength and appearance.

spot tack:  the melting of a small amount of solder onto the copper foiled pieces of glass at joints, or the center of a line in order to secure the pieces, preventing movement.

streakies:  glass sheets with streaks of color running through them.  Colors may be varied against a background of yet another color, either in opalescent or cathedral glass.

tapping: one of the methods of breaking a score.  A ball-ended glasscutter is used to tap along the score from underneath to shock the score into breaking.  A change in "glass resonance" while tapping will indicate the score has started to break.

tinning:  the application of a thin coat of solder completely covering the surface of another metal to stiffen it.  This is usually performed when you are unable to continue the complete soldering of the work, after spot tacking the glass pieces together.  By doing this, you avoid oxidation on the copper foil.