Glasshas been made in one fashion or another for at least 4000 years. The Egyptians were noted for their cobalt glass which they prized as highly as their jewels.
The primary ingredient in glass is sand, also known as silicon dioxide. To make glass, the sand is heated in a furnace until it melts. As the liquid cools, it solidifies into glass. The liquid glass if very viscous and can be molded into various shapes, by pressing into a mold, shaping by hand, or by blowing, either into a mold or by manipulating the glass as it is blown.
Other materials usually go into the furnace with the sand. Calcium carbonate is added to lower the melting point of the glass. All sand has impurities of one kind or another. Ingredients are often added to modify those impurities. Each manufacturer has their own recipe for making glass to certain specifications. Some ingredients are added to make the glass stronger, more heat tolerant, or to meet other purposes.
Glass used to make cut glass, has a high amount of lead oxide added. This makes the glass stronger and more resistance to cracking when heated. It is also what makes the glass ring with a musical tone.
Fundamentals of Cut Glass
Cut Glass is not really "cut". It is actually ground with a wheel made of stone, or more modernly, with a wheel containing diamond chips in the edge. Cutting is done under a stream of water to cool the glass and to wash away the small particles of glass from the grinding wheel.
Glassblower blowing a piece using a bucket to protect other workers if the glass shatters.
Cutting a pattern into a bowl
Cutting a glass
The glass object that is to be cut is called a "blank". A pattern is drawn on the blank, using a wax pencil or marking pen, which is used as a guide by the cutter. The edge of the grinding wheel is "V" shaped and produces a groove the size of the "V". To cut an intricate pattern requires the use of many wheels of varying size.
After the pattern has been cut, the glass is then polished. Early polishing was done with wooden wheels of the same shape and size as the cutting wheels. Each groove was polished individually, requiring a great deal of time. In more recent times, polishing is accomplished by dipping the piece in hydrofluoric acid, the only acid strong enough to dissolve glass. This process is known as "acid polishing.
Sometimes a glass piece may be layered glass. That is when a layer of glass of a different color is applied to the outside or inside of a blank. When the cutter cuts through the outer layer, the under layer becomes visible. If the outer layer were blue and the inner clear, then it would be termed "blue cut to clear".
When washing cut glass, it is important to take several precautions.
1.Line the sink bottom with a rubber mat or with a bath towel folded to fit. Use towels to cover the sink sides.
2. Use only luke warm water. Cut glass may shatter if exposed to a rapid change in temperature.
3. Use a mild dish detergent.
4, A soft brush such as a tooth brush may be used to clean the groves and intricate patterns.
5. Let pieces air dry on a soft surface, such as a rubber mat or soft towel.
Cleaning
Most hard to clean pieces usually have lime deposits from having been used to hold water, or they may be scratched. If lime is the problem, vinegar may remove the deposit. If the stain is severe, Lime Away or CLR cleaners may be used with extreme caution. If this does not remove the discoloration, the piece is most likely pitted or scratched. If this is the situation, the piece will have to be cleaned by a professional who uses glass polishing techniques. This process requires the use of expensive equipment and considerable time and is therefore a rather expensive proposition. The value of the piece should be weighed against the cost of professional cleaning.
As with nearly any item of value, there are always those who are willing to make counterfeit items. Most of the time for money, but occasionally just to prove that it can be done.
The antique market has been flooded with antique reproductions from various Asiatic and European countries.
Fortunately, the only cut glass known to be counterfeit was produced by an American. No one seems to know where he got blanks, but the cutting was done by laser which accurately follows a pattern, either from a previously cut piece or a drawing, and controls a cutting wheel, making a piece on which the cutting is identical to the original.
Identifying such a piece relies mostly on identifying the blank as being new.
As new molds tend to be more perfect than old ones, the glass tends to be much smoother. Some individuals can "feel" this difference. To the eye, it will tend to have a more shiny appearance, especially on those surfaces that have not been cut.
The uncut surfaces tend to be flat, unlike old pieces such as plates and bowls which have uneven uncut surfaces.
New glass tends to have a higher sodium content than old glass. As sodium attracts water, it is felt by some that the appearance and feel is due to water vapor on the surface of the glass.
Fortunately, these were produced to make money, so the patterns cut are almost exclusively those worth the most. This puts these pieces out of the range of most buyers, so unless you are willing to pay thousands of dollars for a piece of glass, the likelihood of buying one is quite rare.
There are many original blanks produced by companies such as Hawkes, that were never cut and are still in existence. Whether any of these have been used to make reproductions is unknown. If they have been used, it would be nearly impossible to distinguish the new from the old.
PressRED STAR to go to Blackhawk/Ohio Valley websites
The national organization is the American Cut Glass Association (ACGA). The national organization has a number of chapters scattered across the country. Not all of the country is covered by a chapter. Chapters are the smallest units of the national organization.
Chapters are the best places to learn about the various aspects of collecting and learning about cut glass. Most chapters hold meetings in various members homes where everyone has an opportunity to observe many different pieces close-up. Members of this organization are among the most open when it comes to providing information about cut glass.
The chapters also host the national conventions and weekend affairs known as "Brilliant Weekends" which resemble mini-conventions. Most chapters will allow guests to attend one or more meetings without actually becoming a member. The National has a rule that a person must belong to the National in order to join a Chapter.
If you enjoy cut glass, then joining the National and a Chapter will provide the ultimate in colleting enjoyment and learning.
Determining the age of a piece of cut glass develops with experience, however, there are a few pointers that can help.
First, American cut glass is generally divided into several periods. Up to about 1840 is the Early Period. The Middle Period extended to around 1870 when the Brilliant Period began. From 1900 to WWI is generally referred to as the late Brilliant Period. Glass manufactured and cut after WWI is generally referred to as "new" by cut glass aficionados.
Few pieces of early glass survive, and those that do are generally engraved pieces. Cutting through the middle period was generally limited to quite wide
cuts, such as thumbprints and panels. Another mark of Middle period glass was the ring neck. Usually one or two faceted rings were on the neck.
Cutting during the early Brilliant period consisted mainly of geometric patterns. At first designs were all straight lines. Later curved lines called vesicas were learned which expanded the number of patterns tremendously. Finally, the latter portion of the Brilliant period saw the advent of naturalistic cutting depicting animals, flowers, vines, etc. About 1902, the "buzz saw" or "pinwheel" design became very prevalent.
After WWI, patterns again became more simplified and the glass became much thinner. Early glass often was 1/2 inch in thickness and sometimes as much as 5/8 inch. This contrasts to later glass that generally was no more than 3/8 inch in thickness.
Using these guidelines will help educate you in your attempt to learn how to make estimates of age.
Many people are confused about the difference between CUT glass and PRESSED glass. Pressed glass has the pattern pressed into the glass when it is molded. Cut glass has the pattern cut after the basic shape has been molded. Pressed glass is sometimes referred to as Pattern glass, as it was a method that could be used to manufacture many pieces in various colors.
Cut glass will not show any mold marks, as they are cut away or polished off during the process of cutting the pattern.
Pressed glass will nearly always show the mold marks, a very thin raise line caused by glass filling the very small gap where the mold parts come together. Most molds were made with three or four part molds.
Some pressed glass may have the mold marks disguised by part of the pattern, but close inspection will nearly always reveal them.
Generally, cut glass will have very well defined, patterns even on the small intricate patterns, whereas pressed glass nearly always has a slight blurring on the small details.
`There were some pieces of pressed glass that were very high quality, and at first may be mistaken for cut glass, but close inspection will reveal the difference.
A compound called "Magic Snake Oil" glass cleaner can be used as an alternative washing method. It requies a container of at least six gallons in size in which to soak items. The method has been tried by the author and found to provide a greater sparkle than the above method.
The washing compound is available from:
Warren & Teddie Biden
House of Brilliant Glass
7400 SW Hunt Club Dr.
Portland, OR 972223-3413
Tel. 503-246-9930
This information is provided as a service only. No waranty is expressed or implied.
