Since the invention of paper by Cai Lun in 105, bamboo scripts are gradually replaced as the common medium of texts, and the Confucian classics become much simplified in style. Scholars feel much relieved with learning, in reading and writing, in particular. Meanwhile, owing to expansion of education objects and writing space, the paper-based texts tend to be popularized even with illustrations. During the later eastern Han dynasty, the appearance of stones for inscription can be deemed as a complement of the paper.