It is the process of coating is the underlying work to bring the metal surface and the ink into close contact so it will not to come off, and the varnish (lacquer / clear) for protection of the inside and outside surfaces for years to come.
When printing on glossy material, finished image will be different from paper printing. In offset printing, colors are expressed by adjusting the density of each of the four colors CMYK (cyan, magenta, yellow, black), but there are colors that are difficult to express in multiplication of these four colors.
