What Is the Process for Silvering a Mirror?
The Oldest and Newest Until the late Middle Ages, people admired their reflections in pieces of polished metal. Silver would have been the choice of the wealthy, but bronze, tin, or even copper were also used. Ironically, the most technically advanced modern mirror, developed by NASA for space telescopes, is also a piece of polished metal—in this case, aluminum. Glass Mirrors Most modern mirrors consist of a piece of glass that has a thin film of metal on one side. While silver is only one of a number of metals that can be used, the process of applying the metal film to glass is generally referred to as “silvering.” In common household mirrors, the silvering is on the back side, or “second surface,” where it is protected by a backing of shellac or special paint. Mirrors made for use in fine optics, such as telescopes, have the silvering on the front, or “first surface.” Amalgam Mirrors The earliest mirrors made this way were “amalgam mirrors,” which used an alloy of tin and mercury.
