Glossary of Glassmaking Terms
Glassblowing - This process involves collecting molten glass melted in a high temperature furnace and shaping it on the end of pipes and punties using tolls that range from newspaper to high tech metals.
Punty - Most often a solid tipped rod with a hollow or solid shaft that is used to take the glass from the pipe so the lip can be formed.
Anneal - When glass has been heated to a high enough temperature, it must be cooled by a controlled schedule of time and temperature or it will crack simply because of the strain inside the glass caused by the outside cooling faster than the inside. The thicker the glass, the longer the cooling time must be.
Coldworking - This is what is done to glass after it has been annealed. Coldworking as a skill is completely different from hot glass furnace work. All of the operations that involve grinding, blasting, carving, etching, cutting, or polishing are considered coldworking.
Grinding - This leaves a frosted white surface. If a clear polished surface is required, several additional steps are normally needed to remove the large scratches, then the finer scratches, and then finally all of the haze.
Etching - Forming a frosted surface on the glass for the purpose of defining all or part of the design or for changing the texture of the surface. This may be done by abrasive blasting, application of acid, by a copper wheel, stone engraving, or by diamond point scratching the surface.
Cased - A thick layer (or layers) of glass on the outside of a piece created by blowing a cup of colored glass and keeping it hot, then blowing inside the cup with another color or clear glass.
Combing or Combed - Lines of color are threaded or otherwise laid down on a piece and then are pulled perpendicular to the lines with a sharp pointed tool. If the tool has a single point, the pattern runs together at the point. With a multi-point tool, the pattern stays more evenly spaced.
Threading or Threaded - A thin line of glass wound around the body. It is created by touching the the piece the tip of a coned of molten glass on a punty and then turning the piece. Application is easier with threading rollers which are two sets of wheels on which the punty or pipe is placed. Because the wheels are set at an angle, each rotation moves the piece the same distance along the axis of rotation and the thread forms a spiral up the piece.
Floor Model - When a piece ends up smashed on the floor, it is called a floor model :o)