In order to improve the sealing properties and the sliding properties of a sealing film, surface structures are provided on a first side of the sealing film, the greatest thickness of the sealing film being at least 10% greater than the smallest thickness of the sealing film and the greatest lateral extension of the surface structures being less than 500 μm. A slip additive is added to the sealing film in a maximum quantity that results in an S-value of less than 10,000, preferably less than 5,000, in order to achieve a COF relative to steel of dynamically less than 0.3, preferably less than 0.27, and statically less than 0.35, preferably less than 0.3, with the side comprising the surface structures, irrespective of an addition of an antiblock additive to the sealing film.