Copper decorations on lustres are more satisfactory if the lustre is fired. It can, however, be applied over unfired lustre if it is perfectly dry. Lustre applied over India ink will fire off. Very pleasant and delicate effects are obtained by outlining with gold and pen over lustres.
MATT COLORS
Matt colors are opaque and are usually used for backgrounds, in which case they are usually applied by the dusting process, although they may be used exactly as china colors are. After being fired the surface assumes a velvety effect and looks like unscoured gold. Sometimes they are used with ordinary colors. They can be mixed with them but when used in this way they are inclined to lose some of the natural dullness. These colors will stand an unusual amount of firing without fading.
Matt colors can be mixed with white and used the same as oil colors.
If a fine bronze effect is desired, it may be had by stippling gold over fired Matt colors.
It frequently happens that after these colors have been fired, they will rub off, especially, if they have been laid on too thick. In this case make a mixture of a small amount of vitrifiable china tint and the Matt color, making a light wash, and this will fasten the ground. This wash may be blown or stippled on. It may be applied with a shader if the colors are not too soft.
Paste and gold may be applied over fired Matt colors. Roman or unfluxed gold may be used over paste, but unfluxed gold must be used if applied directly on the color.
As these colors are opaque no design will show through when fired. Consequently if any design is to be applied to these colors, it must be cut out. (See cutting out.) Vitrified china colors are used over fired Matt tints—and silver can be used over Matt colors.
These colors cannot be used successfully on such articles as table ware, as they will not stand a great amount of washing. They retain grease, etc., and would soon lose their beauty.