The Reality Reports

A Decorative Pattern Became A Defense: Look closely at an older banknote, certificate, bond, or postage stamp. Behind the portrait and lettering, you may find thin curves woven into circles, waves, rosettes, and repeating borders. This line work is called guilloché. Although the patterns add beauty, they were also designed to make valuable documents difficult to copy or alter. Japan’s National Printing Bureau describes guilloché as both decorative and useful against counterfeiting.

Turn a coin sideways and you may find a row of narrow grooves around its edge. These grooves are called reeds, and the patterned surface is known as a reeded edge. Reeding began as a practical defense against theft. It later became part of coin design, manufacturing, identification, and quality control. The edge is sometimes described as a coin’s third side because it can carry features separate from either face.

A U.S. banknote contains features designed to be examined with ordinary movements and light. Tilting the note can reveal changing colors and moving images that are difficult to reproduce accurately. No single test should decide whether money is genuine. The U.S. Currency Education Program recommends a layered approach: feel the paper, tilt the note, and check it with light.