Calligraphy refers to the different forms and differences of traditional writing fonts and glyphs. Generally speaking, the writing forms of Chinese characters are divided into five categories: seal script, official script, cursive script, running script and regular script, and each category can be subdivided. Shoujinti is a font originated by Song Huizong, which is unique in the history of calligraphy. Because it is quite different from traditional styles such as Kincaid and Tang Kai, it can be called original creation in the history of calligraphy. The thin gold body is smart and quick, and the handwriting is thin and powerful, so as to be thin without losing meat. Its large characters are particularly attractive and beautiful, and it is a style font. Xue Yao in the Tang Dynasty was the ancestor of Shoujin. Xue Yao studied Chu Suiliang. He was thin and hard, with a fine pen and a smooth structure, but he was more dangerous and slender than Chu Shu. Instead of imitating the Book of Chu step by step, he made full use of it, created something, became a habit and became the last stream of the Book of Chu. Preface to Shi Li's Summer Poems is Xue Yao's masterpiece and one of the inscriptions on the cliff of Shicong River. Shicong River Cliff Stone Carving is the largest Cliff Stone Carving in Henan Province. It was carved on March 19th of the first year, and it is divided into two parts: Poems on Summer Vacation and Preface to Autumn Banquet. Both calligraphers are Xue Yao, whose calligraphy is thin and vigorous, and they are called "the father of thin gold body" by calligraphers of past dynasties. Xue Yao's calligraphy was later studied by Song Huizong, and finally created a unique "thin gold book" style.