The first is the requirement of using pen in the process of calligraphy creation. It is emphasized that calligraphy creation needs flexible brushwork to make strokes have a sense of rhythm and dynamic beauty, which is the basic requirement of calligraphy art.
Secondly, "it is not easy to use a pen through the ages" is a deep interpretation of calligraphy art, pointing out that the core of calligraphy art lies in using a pen, and the skills and styles of using a pen remain unchanged throughout the ages. This requires calligraphers not only to master the basic skills of writing, but also to form their own unique style on this basis.
Thirdly, this sentence also reflects Zhao Meng's calligraphy thought. It was in the Song and Yuan Dynasties after Yan Zhenqing that the trend of "two kings" for hundreds of years was broken and carried forward under the guidance of his retro thought. He advocated that "it is not easy to use a pen through the ages", in fact, he asked calligraphers to innovate and create their own style of writing on the basis of retro.
Generally speaking, the phrase "calligraphy makes a fortune, but it is not easy to use a pen through the ages" is a profound understanding and incisive exposition of the essence of calligraphy art, which not only reveals the basic requirements of calligraphy art, but also points out the innovative direction of calligraphy art.