It is a unique musical instrument in China, namely the Four Treasures of the Study. The names of pen, ink, paper and inkstone originated in the Southern and Northern Dynasties. Historically, what "pen, ink, paper and inkstone" refers to has changed frequently. "Pen, ink, paper and inkstone" in Southern Tang Dynasty refers to Zhuge Pen, Huizhou Li Tinggui Ink, Chengxin Tang Paper and Jiangxi Wuyuan Weilong inkstone. "Pen, ink, paper and inkstone" since the Song Dynasty refers to lake pen, Hui ink, Xuan paper and Duan inkstone.