Abstract: Shaped articles which are resistant to attack by fatty substances and chemicals and which have impact resistance comparable to high impact polystyrene are produced by extrusion or injection molding of a composition consisting essentially of high impact styrene-butadiene graft copolymer or a mixture thereof with no more than about 55% styrene homopolymer and small proportions of polyethylene or polypropylene and of a block copolymer X-Y-X in which each X is a polystyrene block of about 5,000 to 10,000 molecular weight and Y is a hydrogenated polybutadiene block of 25,000 to 50,000 molecular weight. The articles are characterized by having a skin which is substantially enriched in polyolefin.