The way to raise a pen. In other words, you can see the subtle traces of strokes between consecutive strokes. Also known as "tie wire", "lead", "lead belt" or "hairspring". Da Zhongguang's "Book Raft" in Qing Dynasty said: "Words and tendons are integrated in the new twist, and the context is constantly pulling." Another cloud says, "People know the power of drawing straight, but I don't know that the power of gossamer is stronger." Song Jiangkui's Continued Book Spectrum. The cursive script says: "Since the Tang Dynasty, it has mostly been a single grass, but the two characters are connected, the number of crosses continues, and the number of days continues and it is gossamer." Although this is what the ancients said, it is not surprising that it has become a serious illness. Ancient artificial grass is true today, so it is harsh. " Calligraphers have always known this sentence: "The line is a tangible turn, and the turn is an invisible line."