Art calligraphy, industrial calligraphy. Around 40 BC, he wrote an article called "Urgent Chapter", saying: "Learn from the tiger, learn from it, and the dragon is not in it." Later generations called his calligraphy Cao Zhang. The Summary of the General Contents of Sikuquanshu said: "The so-called Zhangshujia is named because it is a book, and because it is a book, it changes the grass method. Later generations regard it as an urgent chapter. "
In fact, cursive script was a precedent, which made the Western Han Dynasty shine in the history of calligraphy.