After the Neolithic period, ancient Chinese produced painted, black, and carved pottery. During the Han dynasty, China entered a new ceramic age due to advances in kiln firing techniques. While glazed pottery was produced as early as the Western Zhou dynasty, common production began in the Han dynasty. Production of blue and white porcelain declined in quality between the Yuan and Ming dynasties due to a cobalt shortage but improved under the Yung Lo reign with whiter bodies and richer blues. Dragon and phoenix motifs were most popular on Ming ceramics along with other decorations. The Qing dynasty saw further improvements in ceramic types including underglaze blue, polychrome, and monochrome glazes