Application and Firing: Terra sigillata can be applied by spraying, dipping or brushing at all stages of construction. Apply several coats and burnish or simply polish with your hands or a soft cloth when damp/dry to the touch. Polish between coats for the glossiest surfaces. Terra sigillata can be fired at any temperature but the polished surface will start to break down when fired over cone 04. Use as a slip/engobe up to cone 10 and above. Cones 06-04.