Yan Ti and Liu Ti were collectively called "Yan Jin Liu Gu" by people at that time.
Liu Gongquan is the summarizer and innovator of regular script style. On the basis of studying and inheriting the regular script style of Zhong Yao, Wang Xizhi and others, he read modern calligraphy, studied Yan Zhenqing, incorporated his own new ideas, and created his own style. He created the unique "Liu style" regular script, which served as a model for generations to come and became one of the outstanding representatives of "Tang calligraphy".
His calligraphy is balanced, thin and hard, resolutely pursuing the Wei stele, his stippling is crisp and straight, his bones are strong and his body is tight. "The more expensive the calligraphy is, the thinner and harder it is, the more it can communicate with the spirit." His regular script is slightly more even, thinner and harder than his Yan style, so it is known as "the muscles of the face and the bones of the willow".
Since the Yuanhe period of the Tang Dynasty, Liu Gongquan's reputation has become increasingly high. Emperor Xuanzong of the Tang Dynasty especially cherished Liu Gongquan's calligraphy. He once summoned Liu Gongquan to the front of the palace. Military envoy Ximen Jixuan held an inkstone, and privy envoy Cui Juyuan held a pen. Liu Gongquan used a real book to write on a piece of paper "Mrs. Wei passed down the brushwork to Wang Youjun" cross; in cursive script, he wrote on a piece of paper the eleven characters "Yongchan Temple's True Cursive Thousand Character Wen De Jiafa"; in cursive script he wrote on a piece of paper the eight characters "Predicate Helper Yan Zai Hu Ye". Xuanzong rewarded him with brocades, bottles and plates and other silverware. He was also asked to write a letter of thanks by himself, whether in real or cursive script. At that time, the family of the ministers erected monuments for their ancestors. If they did not get the inscription written by Liu Gongquan himself, people would think it was an unfilial act. Moreover, Liu Gongquan's reputation spread far and wide overseas. When foreign barbarians paid tribute, they specially prepared money to purchase Liu Gongquan's calligraphy. Tang Wenzong once praised his calligraphy, which could not be surpassed by Zhong Yao and Wang Xizhi.
When people start learning calligraphy today, they still prefer calligraphers such as Yan, Liu, Ou, Chu, and Yu of the Tang Dynasty. In particular, the set of regular script norms established by Liu Gongquan is still a model for people to learn from today. Liu Gongquan made outstanding contributions in the reform and development of calligraphy art. He summarized the development of calligraphy in the Tang Dynasty and laid the foundation for the development of regular script as a whole.