Over 30,000 metal movable-type letters were exhibited in an ancient town in southwest China's Chongqing Municipality on Thursday. Visitors can experience the ancient printing and typography technology "movable type" on the scene, and can even take home their favorite letters as a souvenir.  Known as one of the Four Great Inventions of China, movable type printing, developed from the woodblock printing, was invented around 1040 AD in China during the Northern Song Dynasty by the inventor Bi Sheng (990–1051).