The present invention relates to a molding composition comprising (A) a copolymer containing at least one α,β-unsaturated monocarbonitrile and at least one aromatic vinyl monomer, (B) a graft rubber with an average particle size of from 100 to 280 nm, composed of at least one α,β-unsaturated monocarboxylic ester, and at least one graft shell composed of at least one aromatic vinyl monomer and of at least one α,β-unsaturated monocarbonitrile, (C) a graft rubber with an average particle size of from 410 to 1000 nm, composed of at least one α,β-unsaturated monocarboxylic ester, and at least one graft shell composed of at least one aromatic vinyl polymer and of at least one α,β-unsaturated monocarbonitrile, and wherein the ratio by weight of component (B) to component (C) is from 3:1 to 1:1. The invention also relates to the process of producing the molding composition and its use.