Tuesday, September 13, 2005

Silver Deposit Glass / Silver Overlay

Silver deposit glass was first made during the late nineteenth century. Solid sterling silver is applied to the glass by a chemical method so that a cutout design of silver metal appears against a clear or colored glass. It is sometimes called silver overlay.

Another reference we found was this statement: Silver Deposit Glass was a piece of glass which had a pattern outlinked on it, then the glass was placed inside a bath along with a piece of silver. The electrolytic process caused the silver to adhere to the patttern outline. This resulted in a very popular type of glass during the turn of the century.

And a more detailed explaination was found: Ordinary glassware earns the name silver overlay glass when it’s embellished with a silver stencil-like design.

For fashionable young couples getting married after World War II, this type of decoration raised the appreciation of any piece of glass from middling to marvellous.

If you haven’t already inherited a piece of silver overlay glass, you’ve probably noticed examples when visiting elderly relatives or antique shops. As the parents of the baby boom generation continue to downsize and pass on to the next world, where material goods have no meaning (a concept I cannot yet fathom), lots of silver overlay glass is becoming available in the vintage marketplace.

If silver deposit glass or overlay catches your fancy, now is the time to buy.

Silver overlay, the decorative technique of applying silver designs to a glass surface (also called silver deposit glass or silver electroplated glass), was patented by Oscar Pierre Erand and John Benjamin Round for Stevens and Williams Ltd. in Birmingham, England in 1889.

Four years later, it was registered in the United States by John H. Sharling. American ingenuity drove the technology and artistry of silver overlay to its peak of accomplishment by the early 20th century.

Although prices for the best examples now reach into the thousands, many far more useful and affordable pieces are available for about $50. And many of these are Canadian.

Silver overlay glass was made in two distinct periods. The first was from about 1890 to the First World War. A revival followed immediately after World War II that lasted until the 1960s.

During the initial era of production, a very labour-intensive production technique meant high retail costs.

To produce a piece of silver overlay glass, a designer would first study the item to be decorated and decide what pattern would be most suitable.

Swirling Art Nouveau flowers would complement a perfume bottle, a waterscape of bulrushes would be used for a water pitcher, or intertwining grapevines for a wine carafe.

Next, the design would be painted on to the glass surface with a special flux — a mixture of turpentine and powdered silver.

After being fired in a kiln to permanently fix the pattern on to the glass surface, these pieces were placed into a water-filled tank along with a sheet of silver. An electric current was then set up between the silver and the tank walls.

This caused the silver ions to migrate from the sheet and attach themselves to any other silvery surface they could find within the field of the electric current. Their new home was on the silvery flux that had been applied to the surface of the glass pieces.

The longer the process continued, the thicker the build-up of the silver coating — and the more expensive the item.

After about 10 hours, the glass piece would be removed from the bath and buffed to create a glistening surface.

If the layer of silver was thick enough, various silversmithing tools could be used to enrich the detailing of the silver surface.

Sometimes the manufacturer’s name and the word sterling were gently stamped into the silver to assure the buyer of superior quality.

During the 20-year revival of silver overlay that began in the late 1940s, a more economical process was used.

After the design was created, it was printed on sheets of paper with an inky flux. These sheets were then used to apply the pattern to the glass surface for subsequent electroplating.

Today, a wide range of silver overlay items can be found, including serving plates, bowls, tumblers, pitchers, trivets, creams and sugars, salt and pepper shakers, ice buckets, perfume bottles and dresser jars.

Yet another description of this glass states Silver-electroplated glass
British glass, also known as silver-deposit glass, produced c. 1890-1920. A design was painted in a flux, placed in a silver solution and subjected to an electric current, which fixed the silver to the painted surface.

Another interesting clip we located states: Silver Overlay Glass: A short explanation from: http://www.glassencyclopedia.com/silveroverlayglass.html

Silver overlay glass has a design in silver "electroplated" onto the glass using one of several electrolytic techniques. Like all silver, the design tarnishes and becomes black in time. It is easy to miss a lovely piece of silver overlay because the silver looks black and uninteresting. The silver can be very thin, like the Venetian decanter on the left, and this kind is sometimes called "silver deposit glass". Or it can be quite thick and even suitable for engraving.

The origins of silver overlay lie in the 19th century, but who was the first to think of using electrolysis to coat glass with silver is still a mystery. There were several patents for using electroplating techniques on glass registered from the 1870's onwards. These included Frederick Shirley USA (1879), Erard and Round for Stevens & Williams Ltd. (1889) and John Sharling in the USA (1893). But it seems that the electroplating-on-glass process was known beforehand by these people. They were patenting ways of using it.

Most of the techniques of depositing the silver involve painting the design onto the glass with flux containing silver mixed with turpentine, firing this design in a kiln, cooling and cleaning the glass and then immersing it in a solution of silver through which a tiny electric current was passed. The silver was then built up on the area where the design had been painted. An alternative method involved coating the whole surface with silver, painting the design onto the silver with a "resist" and then dissolving away the unwanted parts of the silver.

As you can imagine, it is a very expensive process. Ellen Teller in her very useful article in Glass Collectors' Digest (Nov 89) records that a decanter made in 1893 and had more than $4 worth of silver put onto a 90 cent glass blank, with nearly $5 added for labour costs.

The process of putting the silver on the glass was sometimes done by the glassworks in special decorating sections, or more often done by silversmiths on glass supplied by the glassworks. This is why pieces by Steuben, by Heisey, by Cambridge, and others who had no silver-plating facilities can sometimes be found with silver plated decoration.

There have been some very beautiful items produced with silver overlay designs. They were made in volume in England, the USA, Bohemia, Italy (Venice) and no doubt smaller amounts came from many other places. It was popular until the second world war, but a small amount continues to be produced. Recent inventions for coating the silver deposit at the time of manufacture (ie with rhodium) have successfully prevented it from tarnishing.

And our final note on the subject of Silver Deposit Glass / Silver Overlay Glass is to locate catalogs that feature glass with silver overlay (inlay, deposit, or resist) from the 1920s-1970s. Examples of companies which are known to have made Silver Depoit Glass items are Rockwell, Silver City, American Silver Works, S.L.L. Sterling, Lipman Sterling, National Silver Deposit Ware, Lotus, Claude Sterling, Duncan Bros, Edmondson Warrin, ESCO, Spencer House, Bedford Silver, Glenrose, Depasse Pearsall.