films is about 3 mm in each point of their parallel edges that are of equal length this results for both supporting films in a combined contact area of about 90 in respect of the surface of the first polymer film the supporting films are manufactured of a about 30 u03bcm thick polyester film measured at a test pressure of about 0 5 kpa a grip strip is affixed onto each supporting film with an acrylate adhesive the grip strips together comprise a configuration as illustrated in fig4 whereas the first grip strip which is sketched with reference mark 35 has a size of about 57 u00d7 about 39 mm and is throughout the entire width 57 mm attached to the respective supporting film the second grip strip which is illustrated with reference 36 comprises a size of about 57 u00d7 about 22 mm both grip strips are each attached to the respective supporting film through a about 5 mm wide adhesive connective strip and are manufactured from a 20 u03bcm thick transparent polyester film the first grip strip thus has a strip surface with an equally formed width of about 34 mm the size of the grip surface of the first grip.