A low melting point prefused glass flux or frit is described which contains 15 to 65wt.% silicon dioxide, 10 to 50wt.% lead oxide, 1 to 10wt.% cadmium oxide, 2 to 15wt.% tin oxide, 1 to 6wt.% titanium dioxide, 1 to 4wt.% zirconium dioxide, <20wt.%boric oxide, 20wt.% alkali metal oxides and <6wt.% alumina. The glass is used as a protective layer for overglaze decalcomanias and ceramic decorations. It is resistant to acids and alkalis and inhibits the release of lead and cadmium from the decorations. -- AATA