Joan Bolton King

Sgraffito designs are captured in a coat of liquid enamel by fire-scale (copper oxide) forming on the exposed copper when the enamel is fired. This scale will look brown or black and is unlikely to flake away from the restrictive area of the lines, provided the piece is not cooled rapidly in water.

Any small faults, where too much dry enamel has fallen off, or a line been incorrectly drawn, may now be repaired. Add some more of the liquid, allow to dry, re-define and re-fire. (This procedure is normally easier and less likely to mark the piece than trying to correct the unfired enamel.

Fixing the Sgraffito

Fire-scale drawings need to be protected. A thin layer of flux, fired on top, will give it a reddish-brown finish without affecting the clarity of the surrounding white - pickling off the scale first will produce golden lines under the flux. Alternatively, transparent enamels can be used directly on top of the fired liquid enamels.

Log in to read more....