Ceramic and porcelain can be found in archeological digs thousands of years ago still harboring their vivid mineral glazes. These stable materials are still unchanged even when all the metals tools are long gone. Similar to colored glaze, decals are made of stable mineral colors.
Decals are printed images made from mineral toners. The toners are either silkscreen or digitally printed on special paper coated in a water soluble glue. The colored images are then covered with a coating. When the decal is wet, the image is released from the paper, applied and fired in a kiln at approximately 1400F. Once fired at these colors will become permanently embedded on top of the glaze of the ware.