A ceramic decal is a transfer system that is used to apply pre-printed images or designs to ceramic tableware, ornamental ware and tiles, and glass containers.
A decal typically comprises three layers: the color, or image, layer which comprises the decorative design; the covercoat, a clear protective layer, which may incorporate a low-melting glass; and the backing paper on which the design is printed by screen printing or lithography. There are various methods of transferring the design while removing the backing-paper, some of which are suited to machine application.[1]
The decal method is often used for the decoration of pottery. A special paper is used but the ceramic colours cannot be printed directly[2] and the actual printing is done in varnish and the color then dusted on. The decal is placed colored side-down on the sized ware, rubbed firmly, and the paper then sponged off.[1]
The term "ceramic decal" is an American equivalent to the British English terms "transfer" or "litho".[1]