What do you mean, "cut the net with a golden knife and measure it with a jade ruler"? How can creative works be clean and subtle?

Zhu Qing Shiguang's Book Raft: "Painting can be cleaned like a golden knife, and white as a jade ruler." Jiang Ji, a calligrapher in the Qianlong period of Qing Dynasty, said in "On the Continuation of Calligraphy and the Use of Pen": "The pen is divided into fat and thin, and the weight of ink is the fat of meat, which makes the stippling unclean and not refined. Therefore, learning books should be based on the beauty of willow, taking the fear of Europe as its purity, taking the calligraphy of Su Su and Mi as its branch, taking the interest of Dong and Zhao as its branch, and then taking the post of two kings of Xiang Zan,, and thirteen lines, so as to trace its source, be calm and interesting, and then the Tao can be expected and full of people. " Note: Golden knife: refers to the sharpest knife. Jade ruler: refers to the most precise ruler. As a book, white should be counted as black. Where there are strokes (black), cut off the places where there should be no ink like the sharpest knife; How much should be left without drawing (white) with the most accurate ruler. Whether it is black or white, it should be clean and tidy. Appreciation of Hard Pen Calligraphy Works