The binders used for formation of the first and second back layers include homopolymers and copolymers of acrylic acid monomers such as acrylic acid, methacrylic acid, acrylates and methacrylates, cellulose esters such as nitrocellulose, methyl cellulose, ethyl cellulose and cellulose acetate, vinyl polymers and copolymers of vinyl compounds such as polyethylene, polypropylene, polystyrene, vinyl