ALTHOUGH CALLED ‘PAPER money’, the US dollar is in fact a water-resistant mixture of linen and cotton, with coloured silk fibres running through it. The word ‘dollar’ comes from the thaler, a coin first made at the silver mines of Joachimsthal in Bohemia in 1519. Today there are seven trillion dollars in the world – most of which exist only electronically. Fourteen billion are the familiar green ‘bills’, or notes, and a third of these are held outside the United States. Thus ‘there are more dollar bills in existence than any other branded object, including Coke cans’.