Patent enamels should be used with the same precautions that are adopted in the ease of any other enamel. Enamelling should be done in a warm room. Get a clean flat ground on the work, give one coat of enamel, and do not retouch it. If the first coat is not satisfactory, rub off the gloss, or flat it, because enamel should never be put on a glossy ground; then give another coat. Enamelling should not be done when the weather is damp or foggy.