But first -what is a vitreous paint-?Vitreous paint is a mixture of ground glass and pigment oxide, or a mixture of metallic oxides such as iron, cooper, cobalt, manganese and others.Ground glass contains silica, alumina, borax and lead.Vitreous paint is sold in powdered form, and before it is application to glass, it must be mixed with water and gum arabic or other mixing agents, such as white vin