Cast Glass: from the Glass Encyclopedia and Glass Museum
featuring the cast glass of Shona Firman

Cast Glass: A short explanation
The techniques for making Cast Glass involve creating a paste from powdered glass and colouring agents and filling a fire-proof mould with this paste then firing it in a furnace to melt the glass.

The technique was known in ancient Rome and Egypt, but in the art nouveau period (very early 1900s) it was called Pate de Verre and developed to a very high artistic level by such French artists as Gabriel Argy-Rousseau, Henry and Jean Cros, Albert Dammouse, Francois Decorchemont, Amalric Walter, Emile Galle and Georges Despret. These artists put the coloured glass paste into the mould using a paint brush or similar tool, first filling the sections which would eventually stand out in relief. The background of different colours was then added to a thickness of several millimetres and the centre of the mould filled in some way to prevent the paste from slumping. Argy-Rousseau filled the centre with powdered asbestos. For both cast glass and pate de verre, the filled mould is fired to melt the glass paste and fuse it into a single piece, and then allowed to cool very slowly to anneal the glass.

Some of today's glass artists incorporate computer controls and thermocouples (for measuring high temperatures) in the mould itself, giving them very precise control over the heating and cooling of the glass to avoid damage during the process. These techniques were first developed for making cast glass lenses and mirrors for huge telescopes. When the glass has cooled the mould is removed either by pulling apart the separate pieces or by lifting out the glass object (only possible with certain shapes) or by destroying the mould to release the glass. Further work on the glass, such as polishing or engraving or decorating is then undertaken.

Making cast glass is a slow process requiring a large amount of skilled craftswork. Experience and knowledge is needed to avoid bubbles, cloudiness, and cracking during annealing (cooling). Many cast glass sculptures are solid and quite large. Even a small piece 10cm thick can take a month of carefully controlled cooling to ensure it does not crack, and at 20cm thickness the time required to cool safely will be about four months. It was not until after the 2nd World War that techniques were developed for making very large sculptures using cast glass. Stanislav Libensky and Jaroslava Brychtova were the leaders in this development, but their work in communist Czechoslovakia was not widely disseminated in the West until the Czech Republic was set up and greater freedom allowed. Methods of working with cast glass were also developed in the USA, notably by Howard Ben Tre, in the UK by Colin Reid and others, and in New Zealand by Ann Robinson. Today cast glass is some of the most magnificent and skilfull glass produced.

It has been said that New Zealand has developed its own "Silicon Valley" of cast glass artists. Led originally by Ann Robinson who has been casting glass since the early 1980s, there are a growing number of glass artists in New Zealand who specialise in Cast Glass. Shona Firman, whose symbolic tribal canoe is shown above left; Emma Cambden, Greg Smith, and many others have acheived international recognition and awards for their work. One reason for the success of these cast glass artists has been the work of Gaffer Glass in New Zealand, in preparing and supplying suitable glass for casting. Further down this page you will find the story of Shona Firman and examples of her beautiful cast glass.

If you are looking for cast glass, it is worth searching under different names. Pate de Verre, for instance, or the major producers of cast glass such as Daum or Galle. These links will take you to some of the current listings on ebay.
- click here for Pate-de-verre glass - click here for Daum glass - click here for Galle glass - click here for Cast glass