Ou Yangxun's font structure is tight inside and loose outside, which has some differences with Liu Ti's style and is relatively smooth. The font is exquisite. It is clearly reflected in the inscription of Liquan in Jiucheng Palace.
Contrary to the European style, Yan Zhenqing's calligraphy is generally in a state of loose inside and tight outside, with strict and correct fonts, fine horizontal and thick vertical, and full and powerful strokes, especially in the later "Diligence Monument".
Liu Gongquan's calligraphy is also particularly rigorous, but it is not as rich and clear as Yan Ti, and his strokes are lean and powerful. Different from the perfection of the face, the pen set is angular.