2. Inkstone, also known as "Inkstone". Writing with a pen dipped in ink, pen, ink and inkstone are inseparable. Although inkstone ranks first in the ranking of "pen, ink, paper and inkstone", on the one hand, it is in the leading position, and the so-called "Four Treasures of the Study" inkstone is the first, because it is solid in texture and can be passed down from generation to generation. The naming of the four famous Chinese inkstones began in the Tang Dynasty. They are Guangdong inkstone, She Yan, Yan Tao and Hongsi inkstone. Cheng Niyan rose in the Song Dynasty. Today's four famous inkstones are Duanyan, She Yan, Yan Tao, Chengni and HongLing inkstones, which should be the five famous inkstones. In fact, there are many kinds of Gu Yan in China, far more than these. Pine stone inkstone, jade inkstone and lacquer sand inkstone all occupy a place in the history of inkstone.