"Clear Coat Overglaze" Is the best and safest overglaze. It does not contain any lead or glass powders, only a natural fluxing agent that produces a durable glossy shine on the surface of your fired glass. Completely safe to use on food bearing surfaces. Ideal for use on clear window glass, as well as colored glass like Spectrum, Bullseye, Uroboros and others. To apply, just brush or spray a light coat onto the top surface of the glass being fused. "Clear Coat" has a working range of 1350° to 1550°.