Which three calligraphers did Su Shi call Song Sijia?

Su Shi, Huang Tingjian, Mi Fei and Cai Xiang, also known as Song Sijia, are the calligraphers who can best represent the achievements of calligraphy in Song Dynasty. Su Shi is a literary leader in the mid-Northern Song Dynasty. His poems are widely read, fresh and vigorous, and he makes good use of exaggerated metaphors.

Calligraphy art in Song Dynasty occupies an important position in the history of calligraphy in China, and its main practitioners are Su Shi, Huang Tingjian, Mi Fei and Cai Xiang in Northern Song Dynasty. His achievements are mainly reflected in the running script, and there are also two styles: Kai and Cao. Mi Fei has a small number of seal script and official script, but it is not commendable.