Rise of the press
Modern European coinage begins at the end of the 15th century with the discovery of extensive new sources of bullion in the New World and in central Europe, starting an economic boom and introducing new larger denominations of money to handle the increased volume of trade.
Machines such as the drop press, screw press, rocker press, and roller press were invented to replace the hand-held hammer and dies, increasing speed and precision in coin production.
The introduction of steam presses in the early 19th century allowed for further progress in the minting process. These advances in technology resulted in the coins of today - machine struck, with perfectly round, milled edges, each an almost exact copy of the next.
These advances also set the stage for the adoption of Western concepts of currency worldwide.
Paper money has become an increasingly important part of the money supply, moving from a poor substitute for coinage to the mainstay of modern economies over the last 150 years.