Cameo Glass

In the earliest years of cameo art glass only the wealthiest of families could afford even the smallest pieces. It was so valuable that during World War II, when London was being bombed, entire collections were carefully packed up and secretly shipped to Canada for safe keeping. You can find amazing art glass pieces in Princeton, West Virginia with a selection of both "Made in Heaven" one of a kind pieces and Fenton Cameo Art Glass that has been designed by Kelsey Murphy and Robert Bomkamp. Not all cameo art glass is only for the wealthy. You can find  pieces that any collector can add to their collection.
Kelsey Murphy with some of her Cameo Glass
Cameo glass, glassware decorated with figures and forms of colored glass carved in relief against a glass background of a contrasting color. The blanks are produced by blowing two layers or more. When the glass has cooled, a rough outline of the desired design is drawn on its surface and covered with a protective coating  ranging from beeswax to heavy vinyl. The glass is then etched down to the inner layer, leaving the design outline in relief. The details of the design are carved by hand or with rotary tools or sandblasting.
Cameo glass is a luxury form of glass art usually with white opaque glass figures and motifs on a dark-colored background. The technique is first seen in ancient Roman art of about 30BC, where it was an alternative to the luxury engraved gem vessels in cameo style that used naturally layered semi-precious gemstones such as onyx and agate. Glass allowed consistent and predictable colored layers, even for round objects.
Émile Gallé Cameo Vase
From the mid-19th century there was a revival of cameo glass, suited equally to Neo-Grec taste and the French Art Nouveau practiced by Émile Gallé, and cameo glass is still produced today.
Portland vase
Despite the advantages described above, fragile Roman cameo glass is extremely rare - much more so than natural gemstone cameos like the Gemma, Augustea and Gonzaga Cameo, which are the among the largest examples of many hundreds of surviving classical cameos produced from the 3rd century BC onwards. Only about 200 fragments and 15 complete objects of early Roman cameo glass survive. The best and most famous example of these, and also among the best preserved, is the Portland Vase in the British Museum. Other fine examples, such as the Morgan Cup (Corning Museum of Glass), are drinking cups. Both of these named pieces show complex multi-figured mythological scenes, whose iconography has been much debated. The Getty Villa has another cup, and a perfume bottle with scenes of Egyptian deities. The Metropolitan Museum of Art in New York has a fragment over 11 inches long and 5 inches high.
Judging from the very limited number of survivals, cameo glass was apparently produced in two periods: the early period about 30BC to 60AD, and then for about a century from the late 3rd century to the period of Constantine the Great and his sons. The latter period also saw a brief revival of the art of gem-carving, which had been in decline.
Glass from the later period is even rarer than from the earlier, with only a "handful" of complete pieces known, one of which was excavated in Norway. Its use was clearly restricted to the elite. The Portland Vase is said to have been excavated from the tomb of the Emperor Septimus Severus, for whom it would have been a 200 year-old antique. The most popular color scheme for objects from the early period is white over blue, as in the vase from Pompeii, but other colors are found, such as the white over black Portland Vase. In the early period usually all layers are opaque. By contrast, in the later period, there is a translucent colored overlay over a virtually colorless background. The surface of the top layer elements is flat rather than carved as in the earlier group of pieces.
The technique was used in Islamic art in the 9th and 10th centuries, but then lost until the 18th century in Europe, and not perfected until the 19th century. Nineteenth-century English producers of true cameo glass include Thomas Webb and Sons and George Bacchus & Sons, though ceramic imitations made popular by Wedgwood's bi-colored "jasper ware", imitated by others from the late 18th century onwards, are far more common. Like Wedgwood's designers, they usually worked in a more or less neoclassical style. The French medalist Alphonse Eugène Lecheverel, whose work for Richardson's was exhibited in Paris in 1878. Outstanding English cameo glass artisans were Philip Pargeter (1826—1906) and John Northwood (1836—1902), who first successfully reproduced the Portland Vase in cameo glass, and George Woodall. Cameo glass, roughed out by the etching process provided a popular substitute for genuine cameos in brooches and plaques and similar uses, and there are still many producers today.
Kelsey Murphy
Artistically the most notable work since the revival was in the Art Nouveau period, by makers such as Émile Gallé (1846-1904) and Daum of Nancy, when Roman-inspired subjects and color schemes were totally abandoned, and plant and flower designs predominate. Louis Comfort Tiffany made only a small number of cameo pieces, which were a French specialty in this period, though other firms such as the Czech Moser Glass were also producers.
It seems that in the ancient world the entire process of removing the unwanted white or other top layer was done by drills and wheels - wheel-cut decoration on glass of a single color was very common in ancient Rome. One Roman piece uses six layers. It is not known where the Roman pieces were produced, but for want of any better suggestion most scholars think in the capital itself. It appears likely that at least the making of the blanks was initially in the hands of imported Syrian glass-workers. It is almost impossible to do 6 layers today so how the Syrians did it is still a mystery.
The basic technique used in the manufacture of French cameo glass was acid-etching. After the vases were built up with layers of colored glass, they were then cut back with hydrofluoric acid. The design was protected with a waxy substance called a resist. The process was repeated as often as necessary to create the desired level of detail. The result was a raised design that could be seen and felt with your fingers.
The French makers were not content to make the same type of vases again and again, so they experimented with various techniques to achieve different results. It is thought that the technique of mold-blowing by the firm of Emile Gallé was not added to their repertoire until after WWI. By that time, Emile Gallé had already died.
Robert Bomkamp
Using this technique, the artists first had to carve an original model, from which a mold was made. Molten glass was poured into the mold to create a blank. From there, the techniques were the same – build up the layers of colored glass and then use acid to cut them back. The result was very effective, creating flowers or fruit or animals, that stuck out from the body of the vase and became three-dimensional.
In the United States, Kelsey Murphy uses a gathered glass rather than the mold blown so the layers of glass are much thicker giving a fantastically high relief.
Blown-out vases can be of identical form, but not identical. They will differ in color, depending on the choice of colored glass used to cover the blank. They may also differ slightly in design, depending on the etching.
Gallé produced approximately fifty different models of blown-out vases, from small to huge.
Other companies, such as Daum, employed the technique of mold-blowing, but Gallé embraced the technique and produced the largest number of different blown-out vases.