Opalescent Glass

Opalescent glass is a generalized term for clear and semi-opaque pressed glass, cloudy, marbled, and sometimes accented with subtle coloring all combining to form a milky opalescence in the glass. John La Farge and Louis Comfort Tiffany were two American artists who first experimented with opalescent effects, driven by their desire to use glass in creating beautiful visual scenes in art without painting. Opalescent glass was first developed and patented by John Lafarge in 1879, but it was Tiffany who created the masterworks in glass for which he is still so well known today. Tiffany created totally new colors in glass, new types of glass unparalleled in depth and coloration, and used glass in new forms that evoked the forms of nature.

The opalescent effect is a glassmaking technique used by many manufacturers to greater or lesser degrees of artistry, produced in the cooling process, which creates the milky opalescent effect, which illuminates any coloration when light shines on it. Sometimes the opalescent effect was created along the edge of each piece, often coupled with wavy effects and making for an elegant yet subtle look.

This opalescence is also created in the glassmaking by alternating heating and cooling of the glass and with the addition of chemical additives to create the desired effect. Many U.S. manufacturers made this type of opalescent glass, most notably Fenton, Northwood Hobbs, and American Glass, while Davidson's was the major European manufacturer based in the U.K. and giving their wares the marketing name of Pearline. There is also a type of opalescent glass, which is made in layers, and again the heating and re-heating process is used to create the opalescent effect with the addition of chemical agents. The degree and location of the opalescence is controlled as such by the glassmaking process, and by the thickness of the glass itself as it forms itself in the molds. 

Given the intricacy of some of the designs, the production of the metal molds in sufficient detail was an important part of the process. Franckhauser, who did work for Sabino and other contemporaries of Lalique, did many of the molds for French opalescent glass of the Art Deco period. The French did most of the finer glass of this period, but the English firm of James J. Jobling also created some innovative designs after having earlier sought to sign distribution deals with some of the major French factories. Today, few glassmakers still make opalescent glass primarily due to the toxicity of the chemicals needed to execute the complex glassmaking process. 

There are three kinds of glass, which are called "Opalescent". One is the blue-tinged semi-opaque or clear glass with milky opalescence in its centre, typical of Lalique, Sabino, and Jobling's. This kind of glass glows a golden color when light shines through from behind it, and a beautiful blue when light shines onto the surface from the front.

During the 1920's and 1930's there were many companies in France who made beautiful opalescent art deco creations. Amongst the best known were Lalique, Sabino, Etling, Verlys, Hunebelle, Dieupart at Simonet Brothers, Cesare, Daniolo, Ferjac, P. D'Avesn, Martel. Vernox and Verart were two trade names from Sabino to compete with the cheaper opalescent glass from Verlys, and Verlux was another French trade name of the time. In other countries Barolac in Bohemia, Joblings in England, and Val St Lambert in Belgium were also producing beautiful pressed opalescent glass in the 1930's.

The second kind of opalescent glass has a milky white edge or a white raised pattern decorating a colored pressed glass item. This effect is produced by re-heating parts of the molten glass when it has just started to cool, and heat-sensitive chemicals in the glass turn the re-heated sections white. The easiest way to do this is to present the newly pressed glass item back to the "glory hole" or furnace entrance, and those parts nearest the heat turn white.

The third kind of opalescent glass is hand blown and was normally made from two layers of glass. The outer layer contained heat reactive components such as bone ash. The two-layered piece was blown into a mould with the raised pattern impressed into the metal. After removing the mold, the piece had a raised pattern comprised largely of heat sensitive glass, which turned milky white when reheated. This left the white pattern like a silhouette against the usually clear background.

Rene Lalique (1860-1945) was a French "art nouveau" jeweler and sculptor who became interested in glass in his 30's and rented his first glassworks at the age of 49 (in 1909) near Fontainbleu in France. Over the next thirty years he became the world's leading art glass designer of the art deco period.

Lalique opened his first retail salon in Paris in 1905 selling jewelry and decorative pieces, next door to the Coty perfume premises. Coty commissioned perfume bottles from his friend Lalique, and these commissions soon grew into a thriving glass business for Lalique. At the Paris Exposition des Art Decoratifs et Industriels (source of the name Art Deco) in 1925 Lalque won several medals and had a whole marquee displaying his glass in the "new style".

Lalique glass is a collector's dream. It is ALWAYS marked in or on the glass. There is no such thing as "unmarked Lalique". Also, the glass made during Lalique's lifetime can be easily distinguished from later Lalique because it is marked "R. Lalique" as opposed to the post 1945 mark "Lalique". Some early "cire perdue" pieces were marked with Lalique's thumbprint in the glass.

Sabino Glass was and still is, made in France to the designs of Marius Ernest Sabino. Sabino himself was born in Sicily in 1878 but went to France at the age of four. He followed his father's footsteps in training originally as a sculptor, and that early training can be detected in the exquisite figurines that he sculpted to make the molds for his glass designs.

Sabino fought for the French in the First World War, and after the war he recognized the commercial opportunities for glass products in the newly emerging electric-lighting industry. The company he set up made lighting products (lampshades, lamps, glass panels, etc) and a range of opalescent glass vases and statuettes. They had retail outlets in Paris as well as their production facilities. They won prizes at all the major international exhibitions between the two world wars.

Sabino's opalescent glass had a higher arsenic content than most of his competitors, and we understand that after the war the constituents of Sabino glass were changed to reduce the arsenic content. This is one of the ways in which post-war Sabino glass might be distinguished from earlier production pieces. It is said to feel and look different, pre-war Sabino glass is softer and feels "soapy" (a difference that could be detected in a laboratory). But not everyone has the opportunity to handle enough Sabino glass to know the difference. And there have been conflicting statements made about the constituents of later Sabino glass.

Originally Sabino glass was either marked "Sabino France" because it was intended for export, or "Sabino Paris" if it was intended for sale within France. Post-war production has all been made in France and then exported to the USA. The larger pieces still carry the "Sabino Paris" signature, which was etched onto the base of the pieces. Smaller pieces are marked "Sabino France" molded into the side of the item. The Sabino Company still sells early stock of some items which can no longer be made because the moulds were destroyed.

"Verart" and "Vernox" were two other trademarks used by Sabino during the 1930's. They were developed to compete in the cheaper market for opalescent glass that had been opened up by companies like Holophane (trademark "Verlys").

The war starting in 1939 called a halt to all Sabino production, and after the war Marius Ernest Sabino handed over the management of the company to his nephew/adopted son Monsieur Gripoix-Sabino. Marius Ernest died in 1961, by which time Sabino was again producing opalescent glass using the same moulds that he had designed. All their output was exported to the USA.

In 1978 Mr. Gripoix-Sabino sold the entire Sabino operation (moulds, factory, designs, rights and glass formulae) to the company's American agent Richard Choucroun and his "Sabino Crystal Company". This company has continued to produce Sabino Art Glass in France using the same moulds, the same factory, and the same processes, exporting all their output to the USA, and distributing it world-wide from their head office in Houston, Texas. So their production is it is not reproduction, but rather continuous production.

James A Jobling took over the failing glassworks of Henry Greener's in Sunderland in the North East of England in 1885. He was the principle creditor at the time, but glassmaking was not his main interest and the Company continued to trade under the name Greener and Co. It was not until his nephew, Ernest Purser, became the manager in 1902 that the company started to make major investments in the glassworks, and to move towards a profit-making situation.

After a set-back during the war (1914-1918) there was major re-construction of the works, and in 1921 Jobling's obtained the franchise to manufacture and market PYREX glassware in Great Britain and the Empire (excluding Canada). The name of the company was changed to James A. Jobling and Co. Ltd., and PYREX glass rapidly became the most profitable part of their business. Between 1900 and 1930 the works grew from aound one hundred employees to over a thousand.

During the 1930's Jobling's introduced their OPALIQUE glass, a hand-pressed opalescent glass made from molds commissioned and made in France by Frankhauser, the most prominent Parisian, art-glass mold-maker. The same molds were used for JADE glass, and the quality of Jobling's fire-polished pressed art glass during the mid to late 1930's is recognized to be the highest ever achieved in England. Unfortunately the recession of the 1930's and the War (1939-1945) put an end to Jobling's production of this kind of art glass, and eventually (in 1973) the company was taken over by Corning International Corporation, the USA manufacturers of PYREX, and in 1975 the name of Jobling's was changed to Corning Ltd.