A cosmetic agent for the temporary deformation of keratinous fibers and a method for the temporary deformation of keratinous fibers using the cosmetic agent are provided. The cosmetic agent comprises: a) a cosmetic preparation containing a1) at least one copolymer composed at least of the following monomer units: styrene acrylic acid and/or methacrylic acid; a2) at least one copolymer composed at least of the following monomer units: N-tert-butylacrylamide acrylic acid ethyl acrylate, wherein the weight fraction of copolymers a1) and a2) in the total weight of the cosmetic preparationis about 1.0 to about 10% by weight.