In calligraphy, strokes are called "bones" and the rest are called "flesh". The painting method of directly coloring and shaping without hooking the outline is called boneless painting. There are different opinions about the origin of boneless painting, and the most primitive boneless painting should exist in the Neolithic Age. Starting from the Southern and Northern Dynasties, while drawing lessons from Indian painting techniques, Zhang Sengyou further developed the color concept and techniques of Chinese painting, laying a solid foundation for the maturity of boneless painting techniques.
It is said that in the Southern and Northern Dynasties at the beginning of the 5th century, Zhang Sengyou created a landscape painting technique, which directly dyed turquoise, ochre and white into the colors of mountains, stones, clouds and trees. Bone removal was invented by Zhang Sengyou. Yang Sheng used it to paint landscapes in the Tang Dynasty, which was called "Boneless Landscape", and Xu Chongsi used it to paint flowers in the Northern Song Dynasty. He is the founder of Boneless Flower.