A blend comprising a) from 5 to 40% by weight of a linear block copolymer of vinylaromatic monomers and dienes of the structure (I) S1—(B/S)1—S2 having a flexible phase fraction (B/S)1 of not more than 55% by weight, based on the block copolymer (I) and b) from 95 to 60% by weight of a linear block copolymer of vinylaromatic monomers and dienes of the structure (II) S3—(B/S)2—S4 having a flexible phase fraction (B/S)2 of at least 65% by weight, based on the block copolymer (II), where S1 is a block of vinylaromatic monomers having a number average molar mass Mn in the range from 40 000 to 100 000 g/mol, S2, S3 and S4 are in each case blocks of vinylaromatic monomers having a number average molar mass Mn in the range from 5000 to 20 000 g/mol, (B/S)1 and (B/S)2 are in each case copolymer blocks of dienes and vinylaromatic monomers having a number average molar mass Mn in the range from 15 000 to 40 000 g/mol.