China's painting developed to the Song Dynasty, and gradually appeared in the form of painting poems, which were called painting poems (before the Song Dynasty, they were also called painting poems, but this kind of painting poems was not painting). Therefore, higher requirements are put forward for the painter's calligraphy level. Therefore, people call that kind of painter who has a high level of poetry and painting "three musts" of poetry and painting. The "three musts" of poetry, calligraphy and painting have also become the basic quality and cultural accomplishment of cultural people. In the Ming and Qing dynasties, people attached great importance to the seal on the screen, so they added "seal" to the "poetry book", which was called "four musts".
Li Yong was the "Three Wonders" in the Tang Dynasty (this is also the evaluation of Xuanzong in the Tang Dynasty), and many literati in the Song Dynasty belonged to the "Three Wonders", such as Su Shi and Mi Fei. And Zhao Mengfu in the Yuan Dynasty. Wu Changshuo, Qi Baishi and others.