Chinese Emperor Hien Tsung (A.D. 806-821) was the first to introduce paper money, when his country faced a shortage of copper.
The Chinese at least had the benefit of early printing blocks.
In Tibet, paper money was hand painted on rice paper from an ink extracted from leaves and yak dung.
While coins have the advantage of a long life, bills are, of course, much cheaper to make.
At least two countries, Laos and Paraguay, use no coins at all.