Which two calligraphers does Yan refer to?

"Yan Gu" refers to the calligraphers Yan Zhenqing and Liu Gongquan in the Tang Dynasty.

Both of them have their own regular script style, with thick and round faces, more tendons and less flesh, and the brushwork contains them. Liu is strong and powerful, and wins with strength. Their calligraphy styles are different, each with its own merits, and they enjoy the reputation of "Yan Gu".

Yan Zhenqing's regular script has reached a high level, and he is a master in the history of calligraphy. His calligraphy is magnificent, extensive and profound, and his calligraphy style has changed from advocating thinness to being vigorous, becoming one of the representatives of the prosperous Tang Dynasty. Its regular script is broad and vigorous, and its running script cursive script is also elegant and agile, which is very masculine and has a far-reaching influence on future generations.

Brief introduction of Liu Gongquan.

Liu Gongquan's calligraphy is tall and straight, tight inside and loose outside. His brushwork is sharp and vigorous, with irregular stippling and strict statutes. He is called "Liu Ti" in the world. Liu Gongquan's representative works include Mysterious Tower Monument and Shence Army Monument. The monument of the mysterious pagoda is Liu Ti's masterpiece. This monument is a European square and a swallow-shaped circle, which is called harmony. Its style has a generous and open appearance and a neat and fresh appearance.

Kang Youwei said that if it is simplified to small print, it will be "particularly charming." The calligraphy styles of Yan Ti and Liu Ti are different. One is high-spirited, the other is tall and straight, and the other is fat and thin, each leading the way.