Method and device for identifying products and labeled product

Method for marking of products, in which a marking is applied to a surface of the product, which is used as a labeling (2) a liquid is used which contains at least a proportion of a pigment-free dye (4) and to a product (1) is imprinted that at least in the region of the marking (2) facing the surface (2) is made of polycarbonate, wherein the marking (2) provided product (1) is heated to a temperature above ambient temperature and wherein the marking (2) provided product (1) with a cover (8) is laminated, characterized in that after the arrangement of the marking (2) on the product (1) and is carried out by drying of the marking (2) before carrying out the lamination, whereby as substance at least proportionately unpigmented ink is used.