Engraved glass is a type of decorated glass that involves shallowly engraving the surface of a glass object, either by holding it against a rotating wheel, or manipulating a "diamond point" in the style of an engraving burin. It is a subgroup of glass art, which refers to all artistic glass, much of it made by "hot" techniques such as moulding and blowing melting glass. Glass engraving is one of the "cold" techniques, working on formed and cooled glass. The other main techniques in the cold group are glass etching which uses acidic, caustic, or abrasive substances to achieve artistic effects, and cut glass, which is cut with an abrasive wheel, but more deeply than in engraved glass, where the engraving normally only cuts deeply enough into the surface to leave a mark. Usually, engraved surfaces are left "frosted" so a difference is visible, while in cut glass the cut surface is polished to restore transparency. Some pieces may combine two or more techniques.
There are several different techniques of glass engraving. It has been practised since ancient times, including Roman glass, and professionally engraved glass has always been an expensive luxury, requiring lavish amounts of labour by a highly skilled craftsman or artist. In recent centuries the most notable periods and places of production started in the 16th century, initially mostly in Venetian glass, then later in Germany and Bohemian glass. From about 1645 it was used in the Netherlands, which was producing the finest engraving by 1700, by which time some engraving was used in most glass-making centres in Europe. The late 17th and early 18th centuries were in some ways the peak period of achievement and popularity. From 1730 onwards it received some competition from the new geometric cut glass style developed in England. These related techniques were often combined in a single piece, but the engraving tended to be relegated to less prominent positions.
In the 19th century cut glass continued to dominate, and new techniques of etched glass, cheaper than engraving, also took some of the role formerly occupied by engraving. By the later part of the century, a whole variety of techniques, many including coloured glass, had developed. Engraved glass retained some niches, and was sometimes used in art glass and later studio glass, but no longer had its former importance, although there has been a revival in Britain, with many public commissions for large window-size pieces.
Much glass remains in private collections, and many museums do not display much of their holdings, and often do not display them to the best advantage, which is usually against a dark background. Wineglasses were meant to be appreciated by holding in the hand, and when full any distracting engraving on the other side of the glass was not visible, or much less so.Norman, 50
Techniques
Glass engraving has a variety of techniques. It is an intaglio form, with images and inscriptions cut into the surface of the glass through abrasion; but if the cutting is other than very shallow, it becomes glass cutting in the usual terminology. Tools for wheel-engraving glass are typically small abrasive wheels and drills (very similar to those for cut glass), with small lathes often used. Engraving wheels are traditionally made of copper, with a linseed oil and fine emery powder mixture used as an abrasive. Today stone wheels are often used. However, any sharp point that is hard enough to mark glass may be used, and in the past "diamond-point" engraving has often been used, especially for inscriptions of text. Today this is often called "point engraving",Coleman and the tip of the tool is more likely to be tungsten carbide than diamond. Such engraving might be added to a glass (or window) at any point after the glass was made, and consequently can be hard to date.Osborne, 395
Another form of engraving is "stipple" in which the image is created by a large number of small dots or short lines on the surface of the glass with the use of small diamond-tipped tools. The scratches and small dots made in this method can, in the hands of a skilled artist, be used to produce images of astonishing clarity and detail.Norman, 51–53 A mixture of diamond-point, wheel-engraving and stipple can all be used in the same piece, though most pieces use one of them for most or all of the work. Typically the design, or at least the main outlines, are marked on the glass before engraving begins.
Sandblasting is another technique used in glass engraving. Abrasive is sprayed through a sandblasting gun onto glass which is masked up by a piece of stencil in order to produce inscriptions or images. This is often used for engraving large areas such as windows, and the result is often similar to that achieved by glass etching using acid.Osborne, 395
The engraver might be employed by the glassmaker, or completely independent, buying glass blanks or finished glasses and other pieces to work on. This seems to go as far back as Roman times.Caron, 21 Modern laser engraving on glass is another technique, generally only used for decorative purposes mechanically, for example to reproduce images on mirrors.
Details showing the different techniques
History
To the 16th century Engraving on Roman glass was mostly of ornamental patterns, but some figurative images were made, apparently from the 2nd century AD onwards, more often on bowls or plates than cups. Some of these are rather complex.Caron, 19 and throughout These included both pagan and Judeo-Christian religious subjects.Caron, 22, 30–34 Fragments have been found from Wales to Afghanistan.Caron, 46, note 10
There was some engraved early Islamic glass, but as with the Romans, deep cutting (often called carving) was rather more important.Osborne, 396–397 Medieval Venetian glass also used engraving for ornament, but it was generally subordinate to elaborate "hot work" effects, and work in enamelled glass. Most Venetian glass aimed at extreme thinness and delicacy, making it risky to attempt engraving, which was only done lightly with a diamond point.Osborne, 398 This taste continued through the Renaissance and wheel-engraving was in fact not used in Venice until the eighteenth century, much later than elsewhere.Battie & Cottle, 68
Renaissance Diamond-point engraved glass, probably mostly Venetian-made, though possibly engraved later and elsewhere, became gradually more common from about 1530. Some seems to have been made in Innsbruck, where Venetian glassmakers from Murano were allowed to work for a time under an agreement between the Venetian Republic and Archduke Ferdinand II. As was the case at least until the French Revolution, coats of arms were the centre of many decorative schemes, including several pieces with the arms of the Medici Pope Pius IV (r. 1559–65). The cargo of a ship wrecked off the coast of Croatia in 1583, on its way to Constantinople, included engraved and other types of glass, fragments of which have been recovered after the wreck was rediscovered in 1967.Battie & Cottle, 67–68
From the 16th to the 18th century there was also a good deal of amateur engraving of glass, much of it just inscribing a name, but some with images. This period coincided with the development in gem-cutting of the modern facet-cut diamond, making the essential diamond-point tool readily to hand for many of the wealthy. Windows were also subject to this treatment. There is rarely any difficulty in distinguishing even the best amateur work from that by professional workshops.Battie & Cottle, 67; Osborne, 395
By the later 16th century the efforts of the Venetian Republic to hold on to its virtual monopoly in the production of luxury glass, mainly by keeping skilled workers in the republic, were beginning to fail. Other countries, often led by their monarchs, were keen to have their own fine glass industries, and tempted skilled workers away. This led to a diffusion of the Venetian style to many centres around Europe. The glass made in this movement is called "façon de Venise" ("Venetian style"); the quality is typically rather lower than the Venetian originals, partly from difficulties sourcing the right materials, and the place of manufacture is often hard to discern. Engraved glass was a part of this diffusion, and initially was especially developed in Germany.Battie & Cottle, 68, 71–77
In England Jacob Verzelini, a Venetian glassmaker already working in London, was granted a monopoly for 21 years in 1574 over Venetian-style vessel glass. His workshop developed a style with a large amount of simple but attractive engraving, much of it floral, and with the shapes filled in with parallel lines throughout. The engraver seems to have been Anthony de Lysle, a Frenchman.Norman, 51
It was the Germans who first revived the wheel-engraving of glass; it had remained in use for hardstone carving and engraved gems, which are mostly harder than glass. Caspar Lehmann, a gem-cutter perhaps from Munich, is usually considered the first to engrave glass this way, after arriving in Prague in 1588.Battie & Cottle, 78 Prague had the court of Rudolf II, Holy Roman Emperor, a significant patron of Northern Mannerism in several of the arts. The Habsburg court moved to Vienna after Rudolf's death but the Bohemian glass industry continued to grow in strength, reaching a peak of importance in the 18th century.Battie & Cottle, 78
17th and 18th centuries Glass engraving continued in Germany, and grew rapidly in Bohemia and Silesia, with outcrops in several other countries. By perhaps 1645 glass engraving spread from Germany to the Netherlands,Van Eyk, 101 a great centre of engraving for printmaking and enjoying the huge economic boom of the Dutch Golden Age. Dutch engraving had become the finest in Europe by the end of the century.Battie & Cottle, 78–79
Germany and Central Europe The 17th century saw great technical improvements in glass-making, some of which assisted engravers. In Bohemia chalk was added to the basic potash-lime glass, increasing its strength, workability and refractive index. Glassworks there were often started or promoted by the owners of great estates; the requirement for large amounts of wood for the kilns assisted the clearance of forests for agricultural land. The power to drive the grinding-wheels was typically produced by water mills beside the workshop.Battie & Cottle, 82–84; Osborne, 400
Caspar Lehmann's pupil Georg Schwanhardt moved from Prague to his native city of Nuremberg in 1622, and founded a workshop which lasted over a century, continued by his family and others. Unlike the Bohemian engravers, those in Nuremberg often signed their pieces. The most common shapes made were goblets with covers and beakers with "bun" feet. The engraved decoration, normally restricted to the bowl and top of the cover, included a wide range of subjects, drawing from, but not exactly copying, contemporary prints. Portraits of rulers, coats of arms, scenes from classical mythology and the Bible, emblems and allegories are all found, and "battle scenes in woodland settings" were a speciality.Battie & Cottle, 82–84, 82 quoted; Osborne, 400
Elsewhere in Germany, "patriotic decoration tended to be the norm", and glass engraving tended to be centred on the many princely courts, many of which had a Hofkrystalschneider or court glass engraver with his workshop working largely to service the court, including making glasses, often engraved with his portrait, for the prince to give as presents.Battie & Cottle, 86–87 The exact use of the typical covered cup (pokale) is not entirely certain; it is unclear how often they were made in sets, and whether they were used often, or reserved for very formal feasts and toasting.Battie & Cottle, 85