Enamel is coloured glass. The glass is ground to a fine powder, then laid onto a metal surface and fired in a kiln at a great heat to make it melt and fuse. The design develops out of a series of rough sketches. Silver sheet metal is cut out and shaped. Brooch fittings are soldered onto the back. The design is transferred from a piece of plastic film onto the metal. The brooch uses two different enamel techniques: 'champlevé ' (left) and 'basse taille' (right). In champlevé the enamel is laid into cells or depressions carved out of the metal. In basse taille transparent enamels are used over an engraved pattern, allowing it to be seen through the enamels. Engraving tools are used to cut the pattern into the surface of the metal. Enamel can be opaque or transparent. The brooch uses transparent enamel. It is ground under water to a fine consistency. The ground glass is laid on to the metal surface. The brooch is fired in a kiln. The glass fuses onto the metal surface at around 750 degrees centigrade. The enamel is allowed to cool. Another layer of enamel is applied. The brooch is fired again. Successive layers of enamel are built up in this way to intensify the colour. A carborundum stone is used to smooth the surface of the enamel to the silver edge. The brooch is given a final firing. The metal areas of the brooch are polished with pumice and water. The brooch is finished.