TRIZ

Paper Money:

China, Ninth Century AD. Its original name was 'flying money' because it was so light it could blow out of one's hand. As 'exchange certificates' used by merchants, paper money was quickly adopted by the government for forwarding tax payments. Real paper money, used as a medium of exchange and backed by deposited cash (a Chinese term for metal coins), apparently came into use in the tenth century. The first Western money was issued in Sweden in 1661. America followed in 1690, France in 1720, England in 1797, and Germany not until 1806.