A brief history of glassmaking

A 

The first known glass objects can be traced back to the ancient Eastern emires, in about 3500 BC, building on existing knowledge about glazes, a new material, including sand and metal oxides, was developed. This material – glass – was initially used for small pieces of jewellery and inlays in small statues. Then it was used increasingly for vessels made to hold perfumes, oils, and fragrances. Transparency was not a characteristic of these works. Of greater interest to the early glass artisans was the ability to reproduce the colour- and -structures of highly valued semi-precious stones.

B 

By about 450 BC, artisans in the glass workshops of the Persian Empire had learned to apply other techniques to glassmaking, probably producing vessels of considerable size on a turning wheel. Cutting techniques were also used for some of their complex decorations. Meanwhile, the Greeks still concentrated their energies on ceramics, and used glass simply for coloured inlays in sculptures – especially for magnificent monumental statues in public sites.

C 

However, in the 1st and 2nd centuries BC, an industry of luxury glass items of various forms did emerge in former Greek areas strongly influenced by eastern cultures. This industry was in turn to have a profound effect on the glass art of the early-Roman Empire.

D 

The rise of the Roman Empire (1st century BC) was accompanied by an increase in glass production in the Mediterranean region. Initially glass retained its status as a luxury material – indeed from the earliest years of its development it had been generally considered equal to precious stones and valuable metals. Coloured glass bowls, mosaic-glass plates, and glass vessels with gold décor were very popular with the wealthy. However, as the empire expanded, the steps from luxury to mass production, and from decorative objects to vessels for daily use, were gradually taken.

E 

The grounding for this was the Syrian glassmakers' discovery at the beginning of the 1st century BC that glass, when melted, can be made into shapes by blowing down a hollow metal tube. Thus it became possible for these craftsmen to produce a large variety of vessels for different uses – from simple bottles to more decorative and complex pieces. Starting with the leading Syrian glassworks, glass as a manufactured product spread across the entire area of Roman rule. With mass production, glass increasingly became a trade item – of no minor importance in convincing the so-called 'barbarians' from the border areas such as Germany of the superiority of Roman civilization.

F 

The well-planned network of roads in the Roman Empire ensured that the new shapes of manufactured glass objects, and the newly developed techniques used to produce them, were quickly spread and adopted. Wherever suitable materials were found, the same or very similar glass forms, with hardly any variation in quality, were made. This is true of the Italian peninsula, including Rome itself, where numerous workshops producing high-quality goods existed, as well as of Spain and along the shores of the Black Sea. Because of their particularly well-suited sand and large deposits of soda ash, however, the main centres of glass production remained in Syria, Mesopotamia, and Lower Egypt.

G 

Starting in the 1st century AD, small vessels and utensils in Roman households came to be made predominantly of wheel-blown glass, but also of glass. Beside the large number of everyday small vessels for storing fragrances and medicinal extracts, there were bowls in all shapes – some formed on the humming-wheel; some blown – plates, lamps, and much more. Even vessels technically very difficult to produce have been found, such as playful bottles in the shape of birds or other animals.

H 

Whereas colour characterised the appearance of early Roman glass – in keeping with the Greek tradition – from the 2nd century AD, the transparency and also lightness of the material as well as its shiny surface, came to be valued more. Usually it was left in its natural state, typical are vessels having a blue-green coloration of varying intensity. There was, though, an increasing tendency to apply intricate details, and a few coloured accents can be observed. Different coloured glass was also used for simple handles, or for one or two threads or strings of extra glass wrapped around the rims to give emphasis to the vessels' mouths.

I 

In the late Roman period (3rd and 4th centuries AD) the tendency towards complexity was also reflected in the growing popularity of cut and engraved work. Blowing and the use of moulds were developed in new directions, surpassing the designs of the early period of glass blowing. Later vessels such as the so-called shellfish beaker represented a climax in glassmaking of the later Roman period: fish and similar objects were blown separately, formed with special tools, and melted onto the walls of simply-shaped vessels.

J 

Roman glass art continued to be exemplary, and much of the world-famous Venetian glass art from the early 15th century was based on the revival of such methods as thread-glass decoration or mosaic glass. In fact, most methods of glassmaking and glass-decoration changed very little in the centuries following the Roman Empire. This is true of the development of European glass art, even up to the early 19th century. Until chemistry became an established scientific discipline in the second quarter of that century, glassmaking technology underwent only minor improvements. Even now, however, several of the techniques used in the Roman Empire remain a puzzle that modern glass technicians cannot resolve.