15 ON NONCONDUCTORS

At about the same time that electroplating of silver wasfirst being practiced (circa 1840), plating on nonconductorswas developed for the purpose of electroforming and formakingcopper-engravingplates.Nearlyacenturyagotheartentered into its artistic phase, producing metallic artisticelements on glass, wood, and the like. The one survivingremnantofthisphaseisthegold-orcopper-platedbabyshoe.Earlier in this century the art was put to use in the service ofmorepracticalapplications.Thoseincludegraphicarts,toys,buttons, records, and the like.In most of these applications a number of stages in theplatingprocesswererequired.Typicallythefirstofthesewasa roughening process. That was done mostly mechanicallyand sometimes chemically. As an example of the former wemention sandblasting, while as an example of the latteretching of glass with hydrofluoric acid comes to mind. Thesecond stage is that of sealing, if required, such as in thecaseofwoodenobjects.Thethirdandmostimportantstageistheapplicationoftheconductivelayerwhichthenwillmakeeventual electroplating possible. Here a number of methodswere available to the plater: