Patent ID: 8263208

Claim:
A plastic film comprising: on at least one side a surface structure of parallel rows of elevations (a) interconnected by webs (b) wherein the parallel rows are staggered in such a way that the bases of the elevations of one row adjoin the webs of an adjacent row and form a common valley bottom (c), wherein webs (b) at their highest level have a height, with respect to valley bottom (c) positioned between elevations, which is at least 10 percent lower than height of the elevations (a), with respect to valley bottom (c) positioned between elevations, and the common bottom valley (c) is lower than the highest level of the webs, and wherein the plastic film comprises a material selected from plasticizer-containing polyvinyl acetal, plasticizer-containing polyvinyl butyral, ethylene/vinyl acetate copolymers, ethylene/vinyl acetate/vinyl alcohol copolymers, partially acetalized ethylene/vinyl acetate/vinyl alcohol copolymer, polyethylene terephthalate, polyvinyl chloride, and/or polyurethane.