Each individual mirror is done using the same process that was used over 100 years ago!
History of Mirrors
The history of mirrors began long ago when images were reflected from a pond, lake, or even a well. In ancient times crudely designed hand mirrors, or looking-glass were made from polishing plates from stones or metals such as bronze. These so called mirrors quickly became dull and oxidized. Over thousands of years eventually glass with and without a combination of metals was used.
In the middle ages thin sheets of metal foil were layed flat against the backing of glass producing a more reliable mirror.
Finally in 1835 a German chemist by the name of Justus Von Liebig was the first person to deposit silver on glass. This process, known as silvering is still the similar process used by Frick's Glass & Mirrors today.