Deposition on Nonconductors

At about the same time that electroplating of silver was first being practiced (circa 1840), plating on nonconductors was developed for the purpose of electroforming and for making copper-engraving plates. Nearly a century ago the art entered into its artistic phase, producing metallic artistic elements on glass, wood, and the like. The one surviving remnant of this phase is the goldor copper-plated baby shoe. Earlier in this century the art was put to use in the service of more practical applications. Those include graphic arts, toys, buttons, records, and the like. In most of these applications a number of stages in the plating process were required. Typically the first of thesewas a roughening process. That was done mostly mechanically and sometimes chemically. As an example of the former we mention sandblasting, while as an example of the latter etching of glass with hydrofluoric acid comes to mind. The second stage is that of sealing, if required, such as in the case ofwooden objects. The third andmost important stage is the application of the conductive layer which then will make eventual electroplating possible. Here a number of methods were available to the plater: