US Patent 7743704 Method of printing upon a soap bar

Method of imprinting on a soap bar or soap sheet which includes steps of providing printed matter on the surface of the soap and isolating the surface from water contact, such that the printed matter is substantially water-insoluble to provide a cost effective soap bar or soap sheet having printed matter on a surface thereon. The surface is protected by a protective layer which is substantially water-insoluble. The protective layer can be a varnish layer printed on transfer paper and affixed to the soap as a label. The printing color is durable in water or other predetermined diluents and in water-soap solution.