Characteristics of Cao Zhang's calligraphy: The silkworm head without official script in Cao Zhang Province kept the goose tail, which made it inconvenient to write quickly, so Cao Zhang was replaced by this kind of grass. However, on this grassland, there are many obvious inheritance relations with Cao Zhang. Calligrapher Wang Shitang once said, "It is appropriate for beginners to learn, and it is appropriate to learn today." He also said: "Learning from time to time, not knowing the rules, is asking Fiona Fang without rules, and I have never seen it." "An Introduction to Calligraphy" also said: "If you are still ignorant of Cao Zhang, it is equivalent to learning without a monument, and its vulgarity is self-evident. Thus, it is important and necessary to learn Cao Zhang first, and then learn Materia Medica. 《