The trend of inkstone development during the Song Dynasty (960–1279) followed that of the Tang Dynasty. Inkstones grew more fashionable than porcelain inkstones. As a result, all of the high-class inkstones were inkstones while porcelain inkstones became inferior.
From the Tang to the Song Dynasty, the shape and making of inkstones went through a transformation in the form of a clog. One reason for the change was related to the nature of the stones. During the Song Dynasty, the stones for manufacturing inkstones were mostly made from stratified rocks and those obtained from excavation had a schistose structure. Such structure turned the Song inkstones in the form of a clog into a rectangular shape, deviating from those of the preceding Tang Dynasty which was round on one side. Besides, because of the characteristics of the stones at the time, the Song inkstones in the form of a clog were flatter and the two legs were elevated on two sides. The grinding surface was expanded to a rectangular shape, slanting towards one side. Furthermore, handheld inkstones were developed from Song inkstones in the form of a clog. The major change was the increase in thickness of the inkstone body, and the grinding surface was kept flat and curved acutely at one edge forming the ink-pool. In addition, to make the inkstone lighter, the stone beneath the flat grinding surface was removed forming an empty space. The new design allowed for gripping on the forehead of the inkstones by hand, thereby being called handheld inkstones. From the Tang inkstones in the form of a clog to the Ming handheld inkstones, we can trace a continuous change in the inkstone development. Song inkstones in the form of a clog was an intermediate point in this development.
During the Song Dynasty, ceramics were fashionable and famous for many special glaze colours, among which celadon glaze was commonly used and was unprecedented. Therefore, celadon glaze can be considered a unique characteristic of the Song Dynasty, providing a good reference for us to determine whether or not the inkstones come from the Song period.