In order to improve the adhesive properties of plastic films based on polyethylene and/or polypropylene, films are used which contain an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of from 25 to 75 mol% in such an amount that the vinyl alcohol content is from 3 to 10 mol%, based on the sum of the copolymer and the polyethylene and/or polypropylene, and these films are treated by corona discharge at at least 1 W.min/m<2>.
