The first section of this handscroll is the Haiyu modelbook, a letter written by Cai Xiang in his thirties to his friend Han Qi and an excellent example of Northern Song calligraphy in the style of Yan Zhenqing (709-785). The second section is "Poetry in Rhyme for the Master of the Three Colleges" done by Su Shi at the age of 52. Steady and firm, the calligraphy is not confined to conventional methods and serves as a classic example of Su's free-spirited style. The third is Letter to Mingshu by Huang Tingjian, in which the movement includes the methods of Huaisu's (737-799) brush turns. Strong and thorough, the character forms slant mostly to the right, creating for a high-spirited feeling. The fourth section is the Daowei modelbook done by Mi Fu at the age of 49. It ranges greatly from light to heavy and fast to slow, being a masterful work in terms of technique and spirit. In the early Qing dynasty, the collector Li Zongkong (1620-1689) had these four treasures of Northern Song calligraphy mounted together, the handscroll becoming a standard bearer for the study of Chinese calligraphy.