 Printing technology in the form of movable type was invented by Bi Sheng (毕升; 990 – 1051) in the 11th century. The work of Bi Sheng was written of by Shen Kuo in his Dream Pool Essays (Mengxi Bitan). Movable type, alongside woodblock printing, increased literacy with the mass production of printed materials. This meant that parents could encourage sons to learn to read and write and therefore be able to take the imperial examination and become part of the growing learned bureaucracy. Movable type printing was further advanced in Joseon era Korea, where Bi Sheng's baked clay characters were scrapped for metal type characters in 1234. The movable type of Bi Sheng was later improved upon by Wang Zhen (1290 – 1333), who invented wooden movable type c. 1298, and Hua Sui (1439 – 1513), who invented bronze movable type in China in 1490; yet the Koreans had metal movable type before Hua Sui, and even Wang Zhen had experimented with tin-metal movable type. Although movable type and woodblock printing would remain the dominant types of printing methods for centuries, the European printing press (employing the Hellenistic screw-press) was eventually adopted by East Asian countries.
