Terra sigillata, also called “Terra Sig” or “Sig” is applied to greenware with a soft brush. If you desire a burnished finish, apply sigillata to a bone-dry pot, a few square inches at a time. When the area has lost its surface moisture but is still dark, rub with a soft cotton cloth, plastic bag over your finger, the back of a spoon, or a stone. You may apply several coats, but more than two can cause the sigillata to flake. Terra sigillata does not work well under glazes because its dense burnished surface is less porous and therefore is less easy for glaze to adhere. The ideal firing temperature range is cone 04-cone 02 to maintain burnishing but it can be fired up to cone 10.