Antique Glass Overview
Glass is distinguished from other materials by its transparency.
People like glass because of its shine and the way drinker.
glass refracts the light that passes through it. Glass is also extremely practical. It does not allow liquids to permeate it and is a poor conductor of heat. On the other side of course is glass’s only disadvantage — its fragility. Glass today is something modern humankind takes for granted. There is an involved process before glass objects reach the consumer.
Glass is formed by heating various metal oxides and quartz. In addition to the raw materials of glass (quartz and borax), there are also alkaline substances (potassium or sodium oxide). These make the silicates indissoluble.
The right composition of substances for glass is the result of centuries of experience. Glass was probably first made about 4,000 years ago — perhaps discovered in ancient Egypt by chance.
The production of glass was then a relatively straightforward process. The glass-makers first smelted glass in earthenware vessels over an open fire. The glowing pieces of glass adhered together and were then plunged into cold water where they splintered.
These shards of glass-like material were known as frit. The frit was then ground between millstones under powdered when it was smelted once more to achieve the desired result.
This principle was in use until some time after 1500. Old illustrations often show two glass furnaces: one is for the initial smelting of the raw materials and the second for melting the powdered frit.
The production of glass was changed in the eighteenth century in Britain. Coal replaced wood for the glass furnace but this turned the glass yellow from the sulphur dioxide that is released. This meant that glass had to be smelted in a sealed kiln.
This also made it more difficult to keep an eye on the smelting process. A solution was found by producing softer glass mixtures.
Means of decoration
Glass can be decorated in a number of ways. The most direct method is to apply layers of other glass or to mark the surface during the glassblowing process while the glass is soft. Such results depend on the skill and artistry of the glassblower. Glass has been blown since early times and had reached a state of high art in Roman times.
There are various waysin which glass can be decorated during blowing. One way is to add small pieces of glass or `prunts’. Another way is to spin the glass of the same or contrasting colour so that it forms a spiral on the glass surface. Many of the varying techniques are based upon centuries old traditions.
An entirely different way of decorating glass is to enamel or paint it.
This technique does not rely on the artistry of the glassblower. This is done with either ‘cold’ or fired enamel. Glass can also be gilded with precious metals such as silver or gold. Further ways of decorating glass are by cutting or engraving it. Glass is engraved with a diamond which ‘draws’ a design on its surface and it can also be stippled (a Dutch invention) with either a diamond or softer stylus.
Different effects can be created by making either open or dense stipple marks.
Glass has been cut since early times but etching was discovered by the Swede Sheele who notice that the acidic gases of hydrogen fluoride ate in to glass. Glass can also be ‘etched’ by sand-blasting. Encapsulation is done by placing objects in glass while it is still soft that then become fixed in the solid glass. This method was especially popular in Europe between 1800 and 1850.
Glass production from east to west
The production of glass spread to other countries from Egypt around 1000 BC. The techniques were extensively improved between the sixth and second centuries before Christ.
A very important discovery was made at Sidon in Syria in the first century before Christ – the glassblower’s ‘blowing iron’.
This enabled objects to be made of thin glass. It was a technique that spread throughout the Roman empire to Italy and Spain to the west but also to Gaul (France), Britain, and Germany in the north. The major glassblowing centres were established along the Rhine and in Gaul (France).
Production in the east
In common with many other techniques, glass-making was also largely forgotten following the fall of the Roman empire but this was not true in the east. The most important glass-producing region was Byzantium where new techniques were also developed that can be seen in cut and engraved goblets, bottles, ewers, and mosaics of the era.
Arabs were extremely fond of glass embellished with gilt or enamel and major Arab glass centres were Damascus and Aleppo in Syria.
Very fine coloured glass goblets, bottles, ewers, lamps, and dishes were made in these towns between the twelfth and fifteenth centuries. These were often decorated with bright painting.
Persian glass-making took over the leading position in the fifteenth century and Persian glass even influenced Spanish glass. Surviving Persian glass from this era consists mainly of bottles of green or blue glass.
Medieval European glass
Glass production in the former western Roman empire after its fall only survived in Gaul (France), Germany, Flanders, and Britain.
In the early Middle Ages the preference was for decoration with grooves, flattening, and decoration with ‘threads’
of glass. Several new types of object appeared such as `trunked’ and ’studded’ beakers. Otherwise just simple medicine bottles were made from green glass that was far from perfect.
Glass production even went into decline in the ninth century and many in Christian countries regarded glass as a heathen product. After all the heathens used bottles for their ‘pagan’ burials. Pope Leo IV even banned the liturgical use of glass. Not everyone was of the same opinion.
Bishop Isidorus of Seville in Spain wrote a treatise about glass based on Naturalis Historiae, written by the Roman Plinius. The monk Theophilus wrote an extremely important work about glass —probably during the late tenth or early eleventh century, somewhere along the Rhine.
In a piece about the art of glass he described the constituents of Roman and Asian glass, wrote down many legends, and described the process of glassblowing in great detail.
Venice
Sometime around the birth of Christ, glass was produced in northern Italy. The technique was maintained by cloistered orders and spread from these during the Middle Ages throughout Europe. It was in this region that the one of the most famous glass-making centres was established.
Benedictine monks in Venice specialised in making bottles by the year 1000. Following the conquest and pillage of Constantinople by the crusaders in 1204, many Byzantine glassblowers sought to escape to the powerful trading city of Venice.
They strengthened Venetian glass-making with techniques such as glass mosaics. The first thin and hollow glass-ware and first glass jewellery were made in Venice in about 1250. Soon afterwards the production of glass became a monopoly of the Venetian state. The glassblowing works though were forced to move outside the city. With their extensive use of fire they threatened the safety of the city and hence were moved to the island of Murano.
The first reports of exports of glass from Venice are also recorded around 1250. They also made optical glass for spectacles and window glass.
A great deal of glass incorporating soda from burnt seaweed was made in the fourteenth century. The Venetians also began to make latticinio glass with thin white threads around 1400. The Venetians were also known to make golden coloured glass by chemical means and other colours too with copper and cobalt.
They also decorated their glass by `burning’ colours into it. This is very characteristic of fifteenth century Venetian glass. In the sixteenth century the Venetians mainly decorated their glass with patterns of opaque white threads. Vegetal and abstract designs were also created on the thin-walled soda glass.
In addition to clear cristallo glass, Venice also made opaque white lattimo glass that was translucent but not transparent, millefiori containing tiny rods of coloured glass, and frosted glass with a cracked surface. The glassblowers also produced all manner of decorative forms with glass. The chemical composition of Venetian glass was a secret with severe penalties for anyone who revealed the procedures to make it. Despite this, many Venetian glassblowers left for other parts in the early sixteenth century and became involved abroad in the production of imitations of Venetian glass. Excellent copies of glass d la facon de Venice were made in Spain, France, and the Low Countries. These are so good that it is very difficult to determine whether a piece is made in Venice or elsewhere. The main differentiation is that the metal (body of the glass) of the imitations is not so clear, fine, and thin as that produced on the Venetian island of Murano.
Developments elsewhere in Europe
In Bohemia and Germany they also tried to join in Venice’s success. The glass works there only flourished after the Middle Ages. Many attempts were made in France employing Italian immigrants to make totally transparent and clear glass. Dutch glass makers began to make diamond engraved fluted glasses in the sixteenth and seventeenth centuries and it was the Low Countries too that made glasses with a characteristic ‘winged foot’. It was also quite common for glass made in one place to be decorated elsewhere.
BOHEMIAN AND GERMAN FOREST GLASS
The extensive forests of Bavaria were home to many glass works. The production area lay within an area bordered by the Thuringia and Bavarian forests, and the Alps and Fichtel mountains. Because of iron and potash in the raw materials the glass produced was mainly green.
New types of glassware were created that were primarily functional with the main output being glass beakers but ink pots and alchemists’ and apothecaries’ jars were also made.
This was often decorated with prunts and molten threads of glass. Glass was also decorated with bizarre relief forms. All these products were small icrean size in the fourteenth and fifteenth century. Larger pieces were noss bt made until the sixteenth century.
The most widespread of these are so maigelein: shallow beakers of blown gas
A 17th century Dutch green Romer glass. This type first appeared in the 15th century.
of which the bottom is pressed inwards. There were also much larger Pasglas measured glasses, beakers in the form of cabbage stalk, beakers with finger grips, and vertically ribbed cylindrical beakers. The classical slim and tall beakers of Bohemian glass were made in the fourteenth and fifteenth centuries. Their small stems are externally decorated with prunts of molten glass. The Romer glass was first made in the fifteenth century. These wine glasses were extraordinarily popular in the Rhineland. A bellied glass, shaped like an onion with a curved neck consisting of several plaited tubes of glass also appeared in Bohemia in the late Middle Ages.
ENAMELLING
Every glass works outside Italy strived to improve on Italian glass with their local products but the shape of their glassware is clearly different from that of Renaissance Italy. This is because of different local drinking customs. Wine was drunk in Italy but north of the Alps people mainly drank beer. This caused different demands of glasses. The Humpen beer glasses were made from the middle of the sixteenth century.
At first these were conical in form but later only cylindrical Humpen were made. This latter type had a low sole and sometimes also had a hinged lid. The style of painting was intended to give the impression of an Italian product and this also helped to mask the imperfections in the glass.
Enamelling was commonplace on sixteenth century central European glass. The best period for this form of decoration was reached in the earlier seventeenth century. The quality of glass was then improved through the addition of chemicals.
Another category of glassware was the beakers that bore the owner’s crest of arms.
These were also monogrammed and dated. Others, known as ’state eagle’ Humpen were decorated with the German state arms. Quite separate from these glasses though were the Fichtel mountain ox-head glasses that were painted with pictures of the wooded hills from which the Eger, Main, Naa, and Saale rivers rise. Old and New Testament references, fables, and allegories were also common painted decorations in both the Renaissance and Baroque eras.
Although enamelled glass originally came from Venice it gradually became the speciality of central Europe. This method of decoration was used for more than 250 years.
Spun stem Dutch glass. Spinning a thread of glass of the same or contrasting colour around a glass core is one method of decoration.
Enamel became less expensive in the later seventeenth century so that ‘ordinary’ citizens were able to buy it. Finally it became a product for the masses and when applied to milchglass became a cheap alternative to porcelain.
Finding out the origins of a piece is no easy matter. There are countless different types with regional and local characteristics but these became less pronounced as glassblowers moved to work at different places.
PAINTED TRANSPARENT GLASS
A new manner of decorating hollow glass objects was introduced in the later eighteenth century using transparent enamels instead of opaque ones. The porcelain artist Samuel Mohn of Dresden was the first to use this technique.
His ‘friendship’ glasses are painted with portraits, landscapes, allegories, and verses. He customarily signed his work with Mohn fecit. His son, Gottlob Mohn, established himself in Vienna in 1811 and signed himself G. Mohn in Wien. His first work was the painting of town views.
The Viennese porcelain and glass artist Hothgasser took up this popular subject, working mainly on bell-shaped glasses on long branched stems. He mainly signed his work with his monogram between the ‘teeth’ of the branched stem.
Sometimes though he used his full signature on his glasses. These were given as a present or friendship’s token, or served as souvenir. Kothgasser’s glasses with playing cards were very popular around 1875. Kothgasser’s work was in great demand and hence widely copied but reproductions are easily spotted by the naive compositions and lack of technique.
BOHEMIAN ENGRAVED GLASS
The process of engraving was already known during Roman times but the ancient technique was re-invigorated during the sixteenth century in southern German with fresh demand for this style of decoration. This arose because of exports of engraved crystal from Milan. The so-called ‘mountain’ crystal was rare and hence expensive. This led to people in southern Germany deciding to apply the decorative technique used with crystal on glass. Lehmann One of the most famous engravers is
Kasper Lehmann, engraver to the court at Prague. Until recently he was even deemed to have been the ‘inventor’ or glass engraving.
Engraved ginger glass, circa 1700. Although known since Roman times, it was not re-introduced until the 16th century, in southern Germany. Engraved glass became very popular in the north of the Low
Countries.
He established himself in Prague around 1600 and in 1609 he gained a monopoly from the king for the engraving of glass. Lehmann had a number of students, including Georg Schwanhardt, the most important of them, who returned to his home town of Nuremberg following Lehmann’s death. There were many engravers working in this town but each had his own area of speciality.
Schwanhardt mainly worked with Venetian-type goblets, although Venetian glass itself is not suitable for engraving because it is too fragile. Glass with lime added was used for engraving. This sparkling glass was clear and pure with strong refractory properties. It became known as Bohemian crystal.
Bohemian ‘crystal’ was discovered between 1670 and 1680 more or less simultaneously in three glashutten in southern and northern Bohemia. Knowledge of the process spread quickly throughout Bohemia.
Painting with enamel was depressed here by engraved Bohemian ‘crystal’. The first decorations were copies of motifs used in Venice. Because of the high quality of the new material it quickly became a formidable competitor for Venetian glass. Traders not only succeeded in selling Bohemian glass throughout Europe, it was also shipped to other parts of the world.
When the engraving switched to the Baroque style Bohemian glass was even more successful.
SILESIAN ENGRAVED GLASS
The successful formula of Bohemian glass works was also followed in Silesia. The works of Count Schaffgotsch were very important to this region. The glashut in Hermesdorf in particular produced some fine pieces. This was due to the engraver Friedrich Winter who engraved a series of friendship goblets and beakers there after 1690.
The engraved glass from the works at Lobkowitz in Wiesau and Warmbrunn were also of exceptionally high quality. Silesian glass is characterised by the narrowing at the bottom of the drinking vessel. Although Bohemian glass itself was of higher quality, the exceptional Silesian engraving was better than that of Bohemia.
Glass production was advanced following Prussia’s capture of Silesia from Austria in 1742. Glass production in Silesia and Bohemia began to become less significant in the mid eighteenth century due to a number of factors. These included a smaller market through European wars that had caused economic collapse and also a reduction in the size of the market through the development of porcelain and lead crystal. Superb glass goblets made way for simple beakers. Both form and decoration were simplified and more suited to the new circumstances.
The Bohemian glass industry searched for a way to emerge from the crisis.
One of their developments was milchglas that was supposed to compete with the rapidly growing market for porcelain. Entire sets of tableware and drinking services were produced from 1760 to the mid nineteenth century by works at Harrachov in Bohemia.
The opaque ‘milk glass’ was much cheaper than porcelain but could emulate it in both form an enamelled decoration.
GERMAN DEVELOPMENTS
The discovery of the addition of lime to forest or potash glass in Bohemia was also important for the German glashutten.
This was especially true of those works of the electors of Saxony and Brandenburg which bordered Bohemia. Silesian experience in both glass making and engraving was utilised at Brandenburg works at Potsdam, Berlin, and later also at Zechlin. Potsdam attracted Martin Winter, brother of the highly regarded Helmdorf engraver.
The glass specialist and alchemist Johann Kunckel was given the task of researching the best composition for glass. He is credited with discovery of Zwischengoldglas or ‘gold-ruby’ glass. Other gifted engravers also worked for Brandeburg glass makers in addition to Winter.
Glass from this time is solid and heavy. The foot or stem, drinking vessel, and lid were decorated with leaf motifs. Pieces were lighter after 1720 under the influence of the engraver Elias Rosbach. Zechlin glass though (which had gilt medallions melted into its surface) remained fairly robust.
Knowledge of how to produce Bohemian glass spread via Nuremberg northwards. Important centres were established at Brunswick and Hesse, while the glashutten of Thuringia were also important parts of the German glass industry. Just as with porcelain, the electors of Saxony also initiated establishment of glassworks in their domain.
The Saxon works copied Bohemia so precisely that their glassware closely resembles Bohemian glass. Saxon glass though uses slightly different forms, such as horizontal, diagonal, and faceted rims on the stem and underbelly of the bowl. There is a difference too in the gilded relief and gilded engraving
‘RUBY GOLD’ GLASS
In addition to engraved glass, Bohemian glass works also produced ‘ruby gold’ glass or Zwischengoldglas during the prime era for Baroque style. This type of glass had been known in Roman times but forgotten. Following its rediscovery by Johann Kunckel in Brandenburg, Bohemian glass makers also started to make it. The same type of decoration was employed as was used for Bohemian `crystal’.
This consisted of engraving, silver gilt or gilt leaf motifs placed between two layers of glass. Only a few pieces were double layered at that time.
English lead crystal and Dutch glass
Around 1750, glass that was stabilised with lead became important in Europe. The heavy lead ‘crystal’ was well adapted to practically-shaped pieces following
Painted glass box, circa 1850. This type of movingly painted glass boxes were made in Friesland in the Low Countries Classical lines. Lead crystal has unique properties.
It is absolutely clear and is decorated in an entirely different way. By use of a diamond cutting disc a large number of facets can be created that cause light refraction — acting as a series of prisms. Dutch glass was extensively engraved with diamond cutters and lead crystal became extremely popular there. After 1750, some exceptional Dutch pieces were made by stippling the glass with a diamond.
The solid goblets used for this purpose were partly imported from Britain.
Nineteenth century glass
Bohemian crystal found a strong competitor with English lead crystal cut glass. This was because the lead crystal was ideally suited to the forms of the fashion for Classicism. The Bohemian glass makers reacted by adopting the English cut-glass technique but Bohemian glass was not suitable for cutting. The consequences were therefore limited and the technique was restricted so that cutting remained solely an extension to engraving. The subjects for engraving were determined by the current fashion and this can be seen by the motifs used.
Count Georg Buquoy of Neugrdtzen in southern Bohemia became very taken with Wedgwood’s ‘Egyptian Black’. In common with Friedrich Egermann in Haida, Neugrdtzen began making black Hyalith glass that was mainly decorated in a golden chinoiserie style.
The wares included carafes, coffee services, dishes, and vases. Egermann created Lithyalin, a different form of opaque glass that resembled jasper and agate. Like these stones it could be facet cut. Egermann’s glass works also used a golden yellow glass paint that he invented. This was used on goblets and beakers from 1820. Egermann’s greatest achievement though was his contribution to the enriching of glass.
With the help of copper he was able to create cheap imitations of expensive
golden-coloured ruby glass. Glass makers sought an ever greater range of colours and forms for their wares. On the one hand they attempted to improve the process of applying coloured glass to a clear glass base while on the other they sought to develop new methods.
This led to a new technique in which several layers of coloured glass were applied to a base. It was a process that had originated in China. By cutting away parts of the different coloured layers, all manner of colour effects could be created. The use of several layers of milchglas was particularly popular. With this, when a pattern had been cut out it was further decorated with enamel.
Bohemian glass companies exported lots of this type of ware in the 1850’s. Around 1820 the Bohemian glassworks also made glass that was smelted with embedded plaster or porcelain with portraits of famous persons. From 1830 onwards the glass market changed radically because of the major changes in how glass was made. Until that time each piece was individually crafted by a glassblower. During the nineteenth century factories began to press mould glass. This process made it possible to mass produce glass making.
The artistic level of the output dropped of course but commercial considerations were generally more important than aesthetic ones. Very few managed to avoid this trend. One who did was the Viennese artist Ludwig Lobmeyr, who owned a quality glass making works in Steinsch6nau. He was one of a group of artists who opposed the levelling down and increasing lack of taste of the mass produced wares.
This group studied ancient and exotic forms of glass and this led to their works making new types of glassware with simple and functional shapes. Before this trend gained wider acceptance though it was consumed in an even more radical movement that swept Europe under the Art Nouveau and Jugendstil names. The artists A. Daum and E. GaI16 gave glass-making back its individual power of expression and returned to the old traditions. In the United States Louis Comfort Tiffany was inspired by oriental and classical glass. His work was widely admired and echoed in Europe.
One glass works that copied his lead was the Liitz works at Klostermiihle in Bohemia.
Glass and jewellery
Glass paste and beads were used for jewellery back in the age of the ancient Egyptians. Alexandria supplied the then known world with glass beads during the
ancient Greek civilisation and during the Roman empire. The strings of beads made with them were of different colours. The glass was decorated with wavy melted threads of lighter-coloured glass. The production of beads spread through Constantinople and the other towns of the Roman empire to Europe.
Venice was an important production centre for glass beads in the eleventh century. Imitation gem stones had been made in Bohemia as early as the fourteenth century. In the eighteenth century
Louis XIV style mirror of the 19th century.
They also started to make glass beads. Production of glass beads had started in the German Nuremberg in the sixteenth century followed by the Fichtel mountains area of Bavaria in the seventeenth century, and soon afterwards by Potsdam and Thuringia.
Bead production of importance got under way in France in the seventeenth century.