Lustres have dissolved metals as their essential component. They are mainly applied by brush on porcelain, glass or ceramic objects and are always applied to already fired and glazed objects. Before firing, the objects must be left to dry for a few hours in a warm, dust-free place. Recommended firing temperatures are:Ceramics: 690°C-700°C, Orton cone SSB 018 Porcelain: 750°C-815°C, Orton cone SSB 017-015.