JAPAN
feature the amateur will find this point worthy of note. The decoration with vitrifiable enamels was a process subsequent to the stoving of the glazed piece, and was, in fact, added to a vase which, without it, would have been a finished specimen of blue-and-white. To vitrify and fix the enamels another stoving was required. At Kakiyemon's factory the bleu sous couverte was frequently omitted, but the other processes were identical with those described above.
The colouring oxides of the Imari potters were not numerous. They consisted of copper, manganese, antimony, red oxide of iron, impure oxide of cobalt (for black), and finally gold, which, with a small admixture of white lead or borax, served for gilding, and, added to powdered glass, was used for carmine. The enamels did not undergo any preparatory melting, but were mixed and applied directly by the painter, so that their colours appeared only after firing. The manner of painting differs much from that of European keramists. First, the whole pattern is drawn in black outlines, and the shadows, if any, are merely indicated by black lines. The coloured enamels, if opaque, as red, yellow, and black, are laid on in thin layers, but are applied more thickly if, after melting, they are intended to produce the effect of a coloured glass through which the black lines of the pattern are to be visible. Sometimes designs in relief are produced by first applying white opaque enamel which contains no oxide of tin, but is only a mixture of glass, white lead, and pulverised stone, and then painting the pattern upon this. Mr. Atkinson has analysed ten substances used in preparing colours for the decoration of Japanese porcelain. From these analyses Mr. Korschelt concludes that the substances are quartz (Hino-oka-seki); oxide of iron (Beni-gara); carbonate of lead (To-no-tsuchi); lead-glass (Shiratama); lead-glass coloured dark-blue with copper (Koise); lead-glass coloured light-blue with copper (Usu-se); smalt (Kongo); lead-glass coloured violet with manganese (Murasaki); ultramarine (To-kongo) and metallic antimony (Toshirome).
According to the traditions of the Arita potters, seggars were not used in the early years of the factory's existence.74
