People have seen their reflections in water for hundreds of centuries, but some of the earliest signs of human-made brass and bronze mirrors have been mentioned in the Bible and in ancient Egyptian, Greek, and Roman literature. The earliest glass mirrors, backed with shiny metal, appeared in Italy during the fourteenth century. The original process for creating a glass mirror was to coat one side of glass with mercury and polished tinfoil.

The German chemist Justus von Liebig (1803–1873) in 1835 developed a method for silvering a mirror. His process consisted of pouring a compound containing ammonia and silver onto the back of the glass. Formaldehyde removed the ammonia, leaving a shiny metallic silver surface that reflected the light. Today, most mirrors are made by evaporating metallic aluminum directly on the glass.