Whether "Four Notes on Ancient Poems" was written by Zhang Xu is still controversial, but it is an important work in Zhang Xu's brushwork system. Most of its lines do not emphasize lifting and pressing, but focus on changes in rotation and speed in lines of uniform thickness. The center and side strokes are used together. The stroke often falls on one side of the end of the line, but immediately turns to the center. At the same time, there are often irregularities in the flow, such as "year", "bie" and other words, which have an unpredictable feeling. When connecting the left and right parts, thick lines are sometimes used. This can also be seen in the writing of "Qi" and "Jiang" in Yan Zhenqing's "Liu Zhongshi Tie". Through this point, the relationship between Yan and Zhang can be seen.
The stippling in Kuangcao is different from that in other calligraphy styles. Firstly, Kuangcao stippling is completed in continuous motion and is relatively fast, which requires agility and accuracy in controlling the pen. Secondly, common methods such as dwell and click in other calligraphy fonts cannot be used in Kuangcao. You can only rely more on the control of the wrist and other joints, so you must find a movement method that matches the pointillism shape during practice. For a kind of dot painting, calligraphers can use different brushwork to write roughly similar shapes, but for Kuangcao, only writing this shape naturally and smoothly is advisable. Other methods of operation do not combine learners and appreciators. Lead to another style, but lead away from cursive. There are a few weak strokes in "Four Notes on Ancient Poems", but this does not detract from the flow and sincerity of the entire work. As for most of the lines, it has reached the state of being able to write with ease and become interesting. The cursive script does not depart from the rules but can drive the rules at will. This is a situation that Gao Xian and others have never dreamed of.
What really surprises people in "Four Posts" is the word structure. Due to the influence of reading and appreciation habits, "single character structure" is always an aspect that the appreciator cannot get rid of. Compared with Zhang Xu's other works, this work does not conform to his usual rules of word formation.