Hsiao Chu-Chieh checks a tenmoku (tianmu) ware in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. Tenmoku, known for its variability, became widely popular during the Song Dynasty (960-1279). During its heating and cooling, several factors influence the formations of iron crystals within the glaze. Hsiao began his tenmoku study in 1985. It took him at least 15 days to make a finished product of colorful glaze tenmoku. [Photo/Xinhua]

Hsiao Chu-Chieh puts tenmoku (tianmu) wares into a kiln in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh makes tenmoku (tianmu) wares in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh checks newly-made tenmoku (tianmu) wares in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh checks newly-made tenmoku (tianmu) wares in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh makes a tenmoku (tianmu) ware in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh dries tenmoku (tianmu) wares in the shade in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh makes tenmoku (tianmu) wares in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]

Hsiao Chu-Chieh arranges tenmoku (tianmu) wares in New Taipei city, Southeast China's Taiwan, Feb 20, 2017. [Photo/Xinhua]