Ku chao

Literally “paper mulberry money paper”. Other fibers (such as silk) were added to make imitation more difficult. It was manufactured in the imperial manufactures in Chengdu (Sichuan) and Huizhou (Guangdong), then next to Hangzhou (Zhejiang) from the Southern Song dynasty (1127-1279). The paper was printed with intricate patterns and stamped with  blue, red and black seals.