. . . . . "The plastic substrate used in the invention has a thickness of 5 to 100 ??m, preferably, 10 to 40 ??m and is of a material selected from polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate, polycarbonates and polyimides." .