Abstract: The present invention relates to a coating system containing I) anhydrous, gel-like, high molecular weight polyurethane compositions, which may contain active substances, based on (1) 15 to 62 wt. %, based on the weight of 1) and 2), of a high molecular weight covalently crosslinked polyurethane matrix and (2) 38 to 85 wt. %, based on the weight of 1) and 2), of a liquid dispersing agent firmly bound in the matrix by secondary valence bonds, wherein the liquid dispersing agent contains one or more polyhydroxyl compounds having a number average molecular weight of 1000 to 12000 and an OH number of 20 to 112, wherein the dispersing agent is substantially free from hydroxyl compounds having a molecular weight below 800, and II) solvent-containing, solvent-free and/or aqueous polyurethane topcoats.