The four famous inkstones refer to Yan Tao, Duanyan, She Yan and Chengni inkstones. The four famous inkstones have their own merits. Cheng Ni inkstone has been lost, mainly distributed in Yan Tao inkstone, but the four famous inkstones are famous not because of their ordinary stones, but because of their old pit stones. Cheng Ni inkstone has been lost, which is rare in the market. The old pits in Duanyan and She Yan have been basically mined, and most of them are ordinary stones in the market. Because Yan Tao is remote, there are still some old pit stones left, but because there are many fakes in Yan Tao, most of them are not old pit stones on the market.