The glaze earth (_yu t’u_) in various qualities was supplied from different places. Thus the Ch’ang-ling material was used for the blue or green (_ch’ing_) and the yellow glazes, the Yi-k’êng for the pure white porcelain, and the T’ao-shu-mu for white porcelain and for “blue and white.” This glazing material was softened with varying quantities of ashes of lime burnt with ferns or other frondage. Neither time nor toil was spared in the preparation of the Imperial porcelains, and according to the _T’ung-ya_[215] the vessels were, at one time at any rate, dried for a whole year after they had been shaped and before finishing them off on the lathe. When finished off on the lathe they were glazed and dried, and if there were any inequalities in the covering they were glazed again. Furthermore, if any fault appeared after firing they were put on the lathe, ground smooth, and reglazed and refired. It was not the usual custom with Chinese potters to harden the ware with a slight preliminary firing before proceeding to decorate and apply the glaze, and consequently such processes as underglaze painting in blue, embossing, etc., were undergone while the body was still relatively soft and required exceedingly careful handling. The glaze was applied in several ways--by dipping in a tub of glazing liquid (i.e. glaze material finely levigated and mixed with water), by painting the glaze on with a brush, or by blowing it on from a bamboo tube, the end of which was covered with a piece of tightly stretched gauze. One of the last operations was the finishing off of the foot, which was hollowed out and trimmed and the mark added (if it was to be in blue, as was usually the case) and covered with a spray of glaze. To the connoisseur the finish of the foot is full of meaning. It is here he gets a glimpse of the body which emerges at the raw edge of the rim, and by feeling it he can tell whether the material is finely levigated or coarse-grained. The foot rim of the Ming porcelains is plainly finished without the beading or grooves of the K’ang Hsi wares, which were evidently designed to fit a stand[216]; and the raw edge discloses a ware which is almost always of fine white texture and close grain (often almost unctuous to the touch), though the actual surface generally assumes a brownish tinge in the heat of the kiln. The base is often unglazed in the case of large jars and vases, rarely in the cups, bowls, dishes, or wine pots, except among the coarser types of export porcelain. A little sand or grit adhering to the foot rim and radiating lines under the base caused by a jerky movement of the lathe are signs of hasty finish, which occur not infrequently on the export wares. The importance of the foot in the eyes of the Chinese collector may be judged from the following extract from the _Shih ch’ing jih cha_[217]:--