By Debbie and Randy Coe

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Glass Terminology
by Debbie and Randy Coe

During several presentations we have been asked if we would go over the different terms associated with glass collecting. In thinking about which definitions to use in this article, we thought the logical place to start was to define glass. How would you define glass?

Glass is an inorganic substance whose major component is silica sand. The silica sand is pure white and has been properly washed and cleaned to eliminate impurities. This special sand is mixed with potash and soda ash. Lime or lead also can be combined with other chemicals. The other chemicals are used to determine colors, consistency, opalescent and any other desired properties to achieve a special type and/or color of glass. All these ingredients are then melted together in a furnace at over 2500 degrees.

Annealing- The gradual cooling process of bringing the molten glass to room temperature

Batch- The mixture of ingredients needed to create the desired type of glass

Blank- Undecorated piece of glass

Blown glass- Taking molten glass and blowing air into it to achieve a desired shape

Blowpipe- A hollow iron rod used to blow air into the glass forcing it into the moulds shape

Bobeche- A circle or rectangle that is used to catch hot candle wax and can also be used to hold decorative prisms

Cased glass- Applying a layer of a different color of glass over another layer of glass.

Compote or comport- A small bowl on a stemmed base

Copper Wheel- small copper disks are used to make simple hand cut patterns into the glass

Cream soup- A nappy with handles on 2 sides

Crimped- Scallops or flutes at the edge of a bowl or basket

Cullet or shards- Broken pieces of glass that are recovered from making the glass

Cupped- The outer edge of a vase or bowl pulled toward the center

Cut glass- Glass that has been cut by hand or by a machine using metal or abrasive wheels

Double crimped- Additional scallops or flutes placed onto the first set of scallops or flutes creating a very ruffled effect

Embossed glass- A high relief design that is above the surface in the glass

Etching- Achieving a pattern on the glass by applying an acid over a design

Fan shape- A round vase is worked into an ovoid shape forming a fan

Finial- A decorative design on the top of a lid

Fire Polishing- Putting the finished piece of glass back in the furnace to remove any mould seams or imperfections

Flared- The outer edge of a vase or bowl pulled back out

Flashing- Applying a thin color stain to the object that is then fired on the glass to make it permanent Gathering- Taking a glob of molten glass from the furnace to shape into a desired piece of glass

Gilding- Applying a gold decoration to the glass

Glory hole- A small oven used to make final changes on a piece of glass

Grill plate- A dinner plate that has divisions in it

Ground pontil- The rough pontil mark that has been ground out leaving a polished concave circle

Intaglio glass- A high relief design that is below the surface in the glass

Jack in the Pulpit- A vase with a narrow neck that is pulled out into a exaggerated wide top, also called a tulip vase

Lehr- An annealing oven that has a conveyor belt gradually moving the hot glass to lower temperatures until room temperature is achieved

Mould mark- Ridges in the glass that show where the mold was separated from the glass

Nippy- A small round shallow bowl

Oatmeal glass- Sandwich or other patterned glass that was a premium packed in boxes of oatmeal

Opalescent-  A milky white glass that appears after the refiring of a piece. Heat sensitive materials are used in the original batch of glass to cause this effect.

Opaque- Glass that is not able to be seen through

Optic- A decorative effect that is made in the glass to enhance its appearance

Pie crust edge- Very tight exact size crimping around the edge of a bowl

Pontil- The rough indentation of the bottom of a blown item to indicate where it was broken off from the pontil rod

Pressed glass- It is made by pressing the molten glass into a mould to achieve a desired shape

Ringing- A skilled craftsman applying a small glob of molten glass  to the rim of a vase, bowl or basket. The hot glass must be evenly applied like a ribbon along the edge. The Fenton Art Glass Company is famous for this special technique.        .

Rolled edge- The same as flared but then additionally rolled under

Satin glass- This used to be achieved by applying an acid over the entire surface of the glass and then washing it off.  The surface will be slightly rough and non transparent. Because of EPA requirements, satin glass is now made by sand blasting the entire piece of glass rather than applying an acid solution.

Silver deposit- Involves applying silver into an etched pattern on the glass

Silver overlay- Involves applying silver in a design over the glass

Silver wash- Involves applying a silver paint to achieve a pattern

Straw mark- A stress in the glass that occurred in the manufacturing process. They can be a straight or curved line that resemble a crack. But unlike a crack, do not have light passing through the line or have a prismed effect on the line.

Swung vase- A vase that is physically swung to stretch out its original length

Transparent- Glass that has a clear appearance and can be seen through

Threading- Applying thin streams of glass over the outer layer of the glass

Three in one edge- Three tight crimps followed by one wide crimp repeating around the circumference of the edge

Turn- The amount of glass made in a 4 hour shift

Whimsey-  A regular made item that been artistically changed by the craftsman
Two types of glass that are continually confused are stretch glass and carnival glass. Here is a simplified definition of both. Stretch glass is a pressed glass with no or little pattern that has been sprayed with metallic salts while it is still hot. The resulting appearance on the glass is a stretched look that gives the glass it’s name. Carnival glass is a pressed glass embossed with a pattern or patterns and sprayed while still hot with metallic salts. The appearance is an over all look blending look of blues, greens, reds and other colors.

Hopefully these definitions will be of help while reading different articles in reference books and then in referring to ads with items for sale. There is no comparison though to actually going out and looking at the glass. Hopefully all of you have good malls or shops near you to shop at. Talk to the owners and let them know what you are looking for. Whenever a show comes close to your area, make sure you do attend. Whatever the special dealers have in their display at the show, may not surface again in your area. Many wonderful items turn up at shows that are never, ever seen in shops.




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