She inkstone appeared later than Duan inkstone, which began in the Kaiyuan period of the Tang Dynasty. This kind of stone is tough, moist and beautiful. Su Shi called it "astringent without leaving the pen, slippery without rejecting ink." Guapi is also a hub operation, with golden sound and jade virtue. Thick and strong, simple and thick. "Flint also has a variety of textures, good at its decoration, fresh and elegant (Figure 7.25, Figure 7.26).