Zinc being an auxiliary drier, used in conjunction with redox metals. The primary function of zinc is to keep the film "Open" by retarding Surface dry, thus permitting hardening through out & preventing surface wrinkling, particularly in Cobalt containing films & enamels. Zinc is a powerful wetting & dispersing agent, & when incorporated early in formulation, it greatly reduces the time of mixing & grinding. Because of the extremely light colour, Zinc can be added without discoloring the film.