The remaining colours of the on-glaze palette are more obviously enamels; that is to say, glassy compounds; and as they were, in accordance with Chinese custom, very lightly charged with colouring matter, it was necessary to pile them on thickly where depth of colour was required. Hence the thickly encrusted appearance of much of the Chinese enamelled porcelain. The Wan Li enamels consisted of transparent greens of several shades (all derived from copper), including a very blue green which seems to have been peculiar to the Ming palette, yellow (from antimony) pale and clear or brownish and rather opaque, and transparent aubergine, a colour derived from manganese and varying in tint from purple to brown. Two thin dry pigments--one an iron red and the other a brown black colour derived from manganese--were used for drawing outlines; and the brown black was also used in masses with a coating of transparent green to form a green black colour, the same which is so highly prized on the _famille noire_ porcelains of the K’ang Hsi period. As for the blue enamel of the K’ang Hsi period, it can hardly be said to have existed before the end of the Ming dynasty.[230] Gilding, which was apparently in use throughout[231] the Ming period, was applied to the finished porcelain and fired in the muffle kiln. The gold leaf, combined with one-tenth by weight of carbonate of lead, was mixed with gum and painted on with a brush. The effect, as seen on the red and green bowls (Plate 74), was light and filmy, and though the gold often has the unsubstantial appearance of size-gilding, in reality it adheres firmly[232] and is not easily scratched. Of the other processes described in the _T’ao shuo_,[233] embossed (_tui_ [chch]) decoration was effected by applying strips or shavings of the body material and working them into form with a wet brush. Some of the more delicate traceries, in scarcely perceptible relief, are painted in white slip. Engraved (_chui_ [chch]) decoration was effected by carving with an iron graving-tool on the body while it was still soft. And so, too, with the openwork (_ling lung_), which has already been described.[234] All these processes were in use in one form or another from the earliest reigns of the Ming dynasty, and some of them, at any rate, have been encountered on the Sung wares. High reliefs, such as the figures on the bowls described on p. 74, would be separately modelled and “luted” on by means of liquid clay; and, as already noted, these reliefs were often left in the biscuit state, though at times we find them covered with coloured glazes. It is hardly necessary to add that the same processes were applied to pottery, and that the reliefs took many other forms besides figures, e.g. dragon designs, foliage, scrollwork, symbols, etc. [Illustration: PLATE 85 Vase with crackled greenish grey glaze coated on the exterior with transparent apple green enamel: the base unglazed. Probably sixteenth century.