The application of a thin layer of gold to the surface of an object for decoration. Gold could be applied to furniture, picture frames, ceramics, silver, and metalwork. An ancient practice, gilding was used by the Egyptians and the Chinese. During the Middle Ages a high level of craftsmanship was reached when it was used for illuminated manuscripts and panel painting. It was employed regularly from the 17th century for interior decoration and furniture. There were two main methods for gilding on furniture and frames. Oil, or mordant, gilding was laid on any treated surface. Water gilding, the older method, was laid on a gesso ground, then polished and burnished. On ceramics, early methods included pulverizing gold with lacquer and painting it on to the surface. Later, gold was chemically transformed into a powder, which was applied to the surface and fired at a low temperature. It could then be polished. On silver, a chemical process known as fire-gilding was used to create silver-gilt, later replaced by electroplating. Other metals, such as brass and bronze, could be gilt in this way, making ormolu.