Ru ware is the rarest of all Chinese ceramic wares, having been made for only twenty some years for the Northern Song court. Only sixty examples or so have survived, most of which were preserved in the Qing imperial collection. Ru ware is very evenly and thinly potted and most of the pieces are fully glazed (including foot and base), because in the kiln the vessels were placed on tiny supports called spurs that left only minute "sesame-seed" marks on the glaze. The ware is celebrated primarily for the beauty of its bluish- or grayish-green glaze, which usually has a fine crackle. This "veining," together with the color and tactile beauty of the glaze, encouraged comparisons with polished jade. The tripod shape of this vessel reflects a Han dynasty (206 BCE-220 CE) bronze prototype, a shape that was revived during the Song in bronze and jade as well as ceramic, for use as an incense burner.
  The fairly coarse stonewares of the Cizhou and related kilns of Hebei and Henan provinces have in common a coating of white slip, originally developed to increase their resemblance to wares with more refined white bodies. Cizhou wares are noteworthy for their great variety of decorative motifs. The potters were less concerned with the refinement of their materials than with producing bold patterns with painterly or calligraphic qualities. Their emphasis on decoration foreshadows the future direction of Chinese ceramics. All types of Cizhou ware were for popular rather than court consumption. Their robust decorations were created in various ways: by painting, by incising through the slip to the body or through a top layer of slip to a contrasting-colored slip beneath, or by carving away part of the slip and inlaying those areas with slip of a different color.
  Ceramic innovations of the Yuan dynasty marked a complete departure from the Song tradition of simplicity and restraint in both form and decoration. The flamboyant style of this period did not find immediate favor with native connoisseurs, and much porcelain of this period was exported to the Middle East and Southeast Asia.

None of the individual motifs-cloud forms, lotuses and stylized lotus petals, chrysanthemums, lion finial-are new to Chinese ceramics, but the formats in which they are presented here are entirely new and characteristic of Yuan dynasty style. All of the motifs have auspicious connotations.

  The production of very large blue-and-white porcelains, which began in the Yuan dynasty, continued into the early years of the Ming, but the character of the decoration was transformed to accord with Chinese taste. The more crowded designs typical of the earlier period with their heterogeneous motifs were replaced by sparer decoration, rendered more naturally, such as in the jar that features peach tree branches and bamboo. Such patterns were among the first blue-and-white porcelains to appeal to elite Chinese taste.