A craftsman polishes the body of a semifinished "Jian Zhan", a kind of black glaze bowl, at a workshop in Jianyang, southeast China's Fujiang Province, Oct. 29, 2018. "Jian Zhan", a kind of temmoku glaze or black glaze porcelain, was then used only by emperors of ancient China's Song Dynasty (960-1279). Famous for its nobility and gorgeousness, "Jian Zhan" was numerously exported overseas through the Silk Road on the sea. However, after Song Dynasty, those traditional firing techniques to make "Jian Zhan" failed to be handed down to future generations. In recent years, those ancient techniques were regained through untiring efforts made by local authorities and porcelain artists, and have been listed as one of the national intangible cultural heritages. "Jian Zhan" products are now exported to many countries and regions like Japan and the UK with annual output value hitting 1.65 billion yuan (237 million U.S. dollars). (Xinhua/Lin Shanchuan)