The term gilding covers a number of decorative techniques for applying fine gold leaf or powder to solid surfaces such as wood, stone, or metal to give a thin coating of gold. The gilding of decorative ceramics has been undertaken for centuries, with the permanence and brightness of gold appealing to designers. Both porcelain and earthenware are commonly decorated with gold, and in the late 1970s it was reported that 5 tonnes of gold were used annually for the decoration of these products. Application techniques include spraying, brushing, banding machines and direct or indirect screen-printing. After application the decorated ware is fired in kiln to fuse the gold to the glaze and hence ensure its permanence. The most important factors affecting coating quality are the composition of applied gold, the state of the surface before application, the thickness of the layer and the firing conditions. See "Gilding". Wikipedia. Retreived 2014-12-10.