A rare French Art Nouveau pâte de verre glass "Lizard" vide-poche by, Almaric Walter decorated with a lizard that gives the illusion that it is looking at you a top a which is predominantly burnt orange - canary yellow shallow circular/oblong dish. The vide-posche is signed, "A. Walter"
The name Pate de Verre is French for glass paste, and the technique involves 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 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. In the USA Frederick Carder made pate de verre and cast glass pieces for Steuben glass.
The coloured glass paste was put into the mould using a paint brush or similar tool, first filling the sections which would eventually stand out in relief (like the red dress and apples and dark branches of the picture above left). 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. The filled mould was then fired to melt the glass paste and fuse it into a single piece, and allowed to cool very slowly to anneal the glass. Finally the mould would be 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. Further work on the glass, such as polishing or engraving or decorating was then undertaken.
Making pate de verre is a slow process requiring a large amount of skilled craftswork. Great skill was needed to avoid bubbles, cloudiness, and cracking during annealing (cooling).
Outside of France, and especially in recent years, glass made by fusing glass paste in a mould is called Cast Glass. 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 later developed in the USA and in New Zealand and today cast glass is some of the most magnificent and skilfull glass produced.