The invention relates to a pressure-sensitive adhesive strip composed of at least three layers, comprising an inner layer F composed of a non-extensible film carrier, a layer SK1 composed of a self-adhesive composition arranged on one of the surfaces of the film carrier layer F and based on a vinylaromatic block copolymer composition foamed with microballoons, a layer SK2 composed of a self-adhesive composition arranged on the opposite surface of the film carrier layer F from the layer SK1 and based on a vinylaromatic block copolymer composition foamed with microballoons, where the mean diameter of the voids formed by the microballoons in the self-adhesive composition layers SK1 and SK2 is independently 20 to 60 μm.