Glass

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Medieval Glass

Under Frankish influence glassmakers in northern Europe and Britain continued to produce utilitarian vessels, some of new, robust forms. The decoration of these objects was limited to simple molded patterns, threading, and applied ornaments such as prunts (blobs of glass). Mostly green in color, the glass was at first a soda-glass composition made with ashes of marine plants imported from the Mediterranean, as they had been during Roman times. By the late Middle Ages, however, soda was no longer available, and northern glassmakers turned to the wood ash from their own wood-fired furnaces as a flux, for a potash-lime glass. Because the glasshouses were situated in the forests that provided fuel and ash, the glass made was called forest glass, waldglas. Common glass in the waldglas style continued to be made in the lesser European factories until modern times.

The glory of Western glassmaking in the medieval period, through patronage of the church, was mosaic glass in Mediterranean Europe and stained-glass windows in the north (see Mosaics; see Stained Glass). Mosaics were made of small glass cubes, or tesserae, embedded in cement. The tesserae, cut from solid cakes of glass, could be extremely elaborate, with gold and silver lead inlaid. Little is known of the production of mosaic glass before the 14th century.

Glass windows in churches are mentioned in documents as early as the 6th century, but the earliest extant examples date from the 11th century. The finest windows are considered those from the 13th and 14th centuries, primarily in France and England. Glasshouses in Lorraine and Normandy (Normandie) may have provided much of the flat glass for medieval cathedral windows. The glass was colored, or flashed with color, and then cut into the shapes required by the design. Details were painted into the glass, often with a brownish enamel. The pieces were fitted into lead strips and set in an iron framework. The art declined in the late Renaissance but was revived in the 19th century.

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Renaissance to the 18th Century

Although glassmaking was practiced in Venice from the 10th century on, the earliest known Venetian glassware dates from the 15th century. Concentrated on the island of Murano, the Venetian industry dominated the European market until 1700. The major contribution of the Venetians was the development of a highly refined, hard-soda glass of great ductility. Colorless and highly transparent, the glass resembled rock crystal and was known as cristallo.

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The first cristallo wares were simple forms, often embellished with jewel-like enamel designs. Objects were also blown of colored and opaque glass. By the late 16th century, forms became lighter and more delicate. The blowers exploited the workable nature of their material to produce fanciful tours de force. A type of filigree glass was developed in Venice and widely imitated. With lacelike effect, opaque white threads were incorporated in the glass and worked into intricate patterns. Some vessels were blown entirely of opaque white glass and painted with enamels in the manner of Chinese porcelain. Novelties made of lampworked glass were made at Murano, but Nevers, France, became most famous for this type of ware by the 17th century. Particularly suited to soda glass was the practice of diamond-point engraving, a technique favored in the 17th century by Dutch artisans. By hammering the diamond-point stylus for a stippled effect, they created ambitious pictorial designs.

Glass manufacturers throughout Europe tried to copy the Venetians in their production methods, materials, and decorative vocabulary. Knowledge was spread through the glasswares themselves, through the Art of Glass (1612) by Antonio Neri, and through Venetian glassblowers. Although forbidden by law to leave Venice and to divulge the secrets of their craft, many Murano glassmakers left Italy to set up glasshouses elsewhere in Europe. Each country developed its own façon de Venise, as nationalistic preferences for certain forms or decorations tempered the Venetian model. Italy's influence was ultimately weakened in the 17th century by the development of new glass recipes in Germany and England.

Germany's potash-lime glass, thicker and harder than cristallo, was well suited to wheel-engraved decoration. Caspar Lehmann, at the court of Holy Roman Emperor Rudolf II in Prague, was largely responsible for the development of engraving in the early 1600s. Glass cutters and engravers in Nürnberg and Potsdam became famous for skillfully executed designs in the baroque manner. At the same time, the Germanic glasshouses continued their tradition of enameled and cold-painted glass.

The other improvement in glass that served to diminish Europe's reliance on Venice was the lead-oxide glass formulated (circa 1676) by George Ravenscroft in England. Softer, more brilliant, and more durable than the brittle cristallo, English lead glass was considered the finest glass of the 18th century. English table glass dominated the European and colonial markets and became a model for Continental production. English innovations of the mid-18th century were glasses with air or opaque-enamel twists encased in the stems. Among the most prestigious forms of the period was the English cut-glass chandelier. Lead glass, especially suited to cutting, reached its full potential in the neoclassical wares of the Anglo-Irish period (1780-1830).

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American Glass

Glassmaking was the first manufacture undertaken in America, with a glasshouse built at Jamestown, Virginia, in 1608. The first commercially successful glassworks was that of Caspar Wistar in Salem County, New Jersey, between 1739 and 1777. Immigrant German artisans there and at other factories produced bottles, windowpanes, and some table glass in Germanic styles. Henry William Stiegel sought to imitate English imported lead glass at his factory in Lancaster County, Pennsylvania, from 1763 to 1774. The most important glassworks built after the American Revolution was that of John Frederick Amelung in Frederick County, Maryland, which was in operation from 1784 to 1795.

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19th and 20th Centuries

The stylistic history of glass in the 19th century is dominated by rapid advances in glass technology and by the rediscovery and adaptation of older methods.

Mechanical pressing, introduced in the U.S., was a cheap, fast means of production that greatly expanded the role of glass in the home and in industry. Before 1850, wares were pressed in intricate lacy designs that offset a cloudiness in the glass caused by contact with the cooler mold. Simpler designs popular from the 1840s on, known as pressed pattern glass, were available in many forms. The more expensive cut glass declined in favor because of the competition from pressed glass. Only about 1880 did cut glass regain some of its earlier popularity with the elaborate “brilliant” patterns, examples of great technical virtuosity that exploited the refractive properties of quality glass.

Beginning in the late 18th century, a number of Roman glassmaking techniques were revived and modified to suit neoclassical taste. Continental glass factories made a version of laminated gold-leaf glass, called zwischengoldglas. Cameolike effects were attained with encrusted sulphides, and actual cameo engraving and cutting were practiced by artisans beginning in midcentury, culminating in the work of Thomas Webb and Sons (founded 1837), a glasshouse in Stourbridge, England. Paperweights, popular from about 1845, were often made in a millefiori (thousand flowers) design recalling the mosaic glass of ancient times. Renaissance rock crystal inspired a technique of polished engraved glass in the late 19th century.

Bohemia continued to excel in wheel-engraved decoration with the work of such artisans as Dominik Biemann. Other methods, such as cased glass, were practiced in Bohemian factories and copied throughout Europe and the U.S. Chemical advancements led to new opaque colored glass such as lithyalin, which resembled semiprecious stones. Transparent enamels and stains were applied to vessels, paralleling the revival of stained-glass windows.

Inspired by the revivals of historical glassworking methods and spurred by the capabilities of improved chemical technology, glassmakers by 1880 were creating new styles of handworked glass, generally called art glass. These were mostly decorative and novelty forms, made in reaction to mass-produced wares. Between 1890 and 1910 the most fashionable styles reflected the international art nouveau movement. Louis Comfort Tiffany in the United States, and Émile Gallé and the firm of Daum Frères (founded 1889) in France, were the leading proponents of the style. They produced glasses of naturalistic shapes, sinuous lines, exotic colors, and unusual surface effects, such as Tiffany's iridescent Favrile glass.

After World War I new interests in texture and formalized decoration emerged, seen in the designs of René Lalique and Maurice Marinot. Beginning in the 1930s, exquisitely clear, colorless lead glass, often engraved, was popularized by several Scandinavian and American firms.

A new era in glassmaking began in the early 1960s with the studio glass movement, led by the Americans Harvey Littleton and Dominick Labino. With small tank furnaces in studio settings, artisans explore glass as an artistic medium. Innovative sculptural forms and decorative techniques are being developed at workshops in the United States and around the world. In the late 20th century the work of artist Dale Chihuly inspired new interest in glass as an art form. The Tacoma Art Museum in Tacoma, Washington, features a large collection of his work.

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Non-Western Glass

Glassmaking was not as strong a tradition in Islamic and Far Eastern countries as it was in the West. Forms and techniques developed that closely reflected their individual cultures; these, in turn, influenced Western forms.

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