The story of Zhang Zhiqin practicing calligraphy

Zhang Zhiqin studied calligraphy and never chose paper and pen. As long as his daily necessities can be used as imitation writing tools, he usually writes on a bronze mirror to correct his posture. There is a story of "running out of pen and ink" in his kung fu practice. In order to practice calligraphy diligently, I dug a Fiona Fang pool with dozens of feet in front of my house. After I finished writing, I washed my brush and inkstone in the pool. The clear water in the pool was dyed black year after year, so I got the postscript created by Zhang Zhi, a "modern grass".