"One of the four great calligraphers in the Northern Song Dynasty.
He is good at running script and regular script. He studied under Li Yong, Xu Hao, Yan Zhenqing and Yang Ningshi, and he can find a new way. The end of the pen is ups and downs, naive.
Cai Xiang (formerly known as Cai Jing), Huang Tingjian and Mi Fei are also called "Song Sijia".