Many people think that the origin of hard-pen calligraphy can be traced back to ancient times, when people used stone tablets and knives to depict tortoise shells and animal bones, which proved that hard-pen calligraphy was an art form before brush calligraphy. However, knives and stone chips are far from the hard pen writing tools we use now, and there are still some differences between description and writing. This is why calligraphy and seal cutting are always two kinds of arts, although they are inextricably linked. Comparatively speaking, I prefer to trace the history of seal cutting back to Oracle Bone Inscriptions.