Polyurethane foam moldings

The invention relates to polyurethanes, in particular polyurethane foam moldings having grooves on the surface of the foam which can be produced by incorporating a polyurethane foam system into a mold or a cavity, characterized in that substances are applied on the surface of the mold or to the surface layers of the cavity which there affect the foaming process in such a manner that arise in the vicinity of these materials on the surface of the foam wells.