silver plating process must be cleaned to eliminate fat and remove all impurities; spinning brushes are used for this and the carrying of cerium oxide in water. After rinsing with distilled water, the surface is coated with a solution of stannous oxide whose reducing action allows the precipitation of the metallic silver from a solution of silver nitrate.
The reflective metallic film is then coated with a layer of copper, which was obtained by nebulization of the metal or by electrolytic coppering; this protect the mirror, over time, from oxidation. Lastly, the layer of copper is coated