Gold has the very useful property of being one of the most highly ductile metals in existence. 5000 or more years ago it was discovered that small chunks of gold could be repeatedly hammered and flattened until an extremely thin gold foil remained. This foil is commonly called gold leaf. Modern gold leaf manufacture generally employs a high-precision rolling mill that can create a gold foil of 0.1 microns in thickness. This is *very very* thin.

Gold foils are used frequently for decorative purposes (Gilding), beam targets for particle physics, and as a gimmick in Goldschlager.