Chinese painting technique name. It is the development of ancient "line drawing". A method of drawing objects with colorless ink lines. Mostly figures and flower paintings. There were many sketch masters in ancient China, such as Wu Daozi, Zhao Mengfu, Gu Kaizhi and Li, who all made outstanding achievements. During the Song and Yuan Dynasties, there were also painters who painted flowers and birds with lines, such as Zhong Ren in the Northern Song Dynasty, Yang Wuxia in the Southern Song Dynasty, Zhao and Zhang Shouzheng in the Yuan Dynasty.