Bi Tu is a calligraphy monograph created by Wei Shuo in the Eastern Jin Dynasty. There are seven ways to write it. Those who are impatient, those who write slowly, those who write slowly. If the pen is close but not tight, the heart and hand are uneven, and the former will be defeated; If the pen is far and urgent, the one who intends to write first wins.
There are also six kinds of pens: the structure is as vigorous as seal cutting, the wind is like grass, the risk is like eight points, the graceful entry and exit is like flying white, the standing is like a crane head, and the depression is like an ancient plum. However, the heart is curved, and every word is wonderful.
This book discusses the works of writing strokes, expounds the methods of holding and using pens, and lists seven basic strokes. Because of its wide spread, this old saying is still listed as Mrs. Wei's work. One of the outstanding points of Pen Diagram is that it is difficult to express the exquisiteness of calligraphy, and the beauty of calligraphy with pen is listed before the "three ends".