The breakthrough came in the late 17th century with the adoption of ridged, or reeded, edges. The idea was simple and effective: a uniform pattern made tampering immediately obvious. Any shaved or altered coin would stand out at a glance or to the touch. This innovation quickly reduced fraud and became one of the earliest examples of practical anti-counterfeiting design.

Today, coins are no longer made from precious metals, yet ridged edges remain. They help machines sort and authenticate currency, allow people to distinguish coins by feel—including those with visual impairments—and maintain consistency across denominations. Beyond function, the grooves preserve a sense of continuity, linking modern money to centuries of careful craftsmanship and problem-solving.