Page:An Elementary History of Art.djvu/341

 Materials. 311 and the Roman ; in which smalts of every variety of shade are employed. Many of the greatest paintings of the old masters have been admirably reproduced in the latter kind of mosaic. Another kind of mosaic work has been lately introduced in the decoration of the South Kensington Museum, in which Keramic tesserae are used. And the figures in the south court of eminent men connected with the Arts are executed in mosaic, both Vitreous and Keramic, from designs by Sir F. Leigh ton, P.R.A., E. J. Poynter, R.A., and other well-known artists. Painting on porcelain holds a high position as a fine art, and has been carried to great perfection in France and England of late years. The processes employed in painting on porcelain, enamelling, and glass-staining, are very similar. The colours used are principally oxides or salts of metals ground down to impalpable dust, and mixed with borax or some fusing substance ; the mediums used for making them liquid are turpentine, oil of turpentine, or spike oil : formerly each artist mixed his own colours, but now they are most frequently obtained ready prepared in tubes and in fine powder : they are laid on with hair- brushes like oil colours, either on the glazed clay or pre- pared metal, as the case may be, and fixed by exposure to heat in an enamel kiln. In another method of painting on china, called " under glaze," the colours are laid on to the unglazed surface of the china : in firing they become embodied in the ground on which they are laid, and the glaze is poured over them. A third kind, known as "Majolica painting," is "done with coloured glazes all made to fuse together at a special heat." In appearance it somewhat resembles Italian lustre ware.