Sun Yunyi (L), inheritor of Boshan chicken oil yellow glaze, talks with a worker about grinding technique in Boshan District of Zibo, east China's Shandong province, Jan. 12, 2019. The formulation and preparation process of chicken oil yellow glaze artworks are complicated. Sun Yunyi continuously searched for high-quality raw materials and conducted repeated tests of making chicken oil yellow glaze artworks. Boshan District has developed a colored glaze industry with about 5,000 practitioners, 30 studios and 13 production enterprises, generating more than 48 million yuan (7.1 million U.S. dollars) per year. (Xinhua/Wang Kai)