A commonplace vinyl ester resin blended with a core-shell polymer additive has been used as a matrix for some typical structural commercial materials to determine the benefits of increased matrix toughness. In a simulation of polymer concrete, the tougher matrix was found to increase the toughness of the concrete by a small amount. Unexpectedly the flexural strength was increased by 30% which has been ascribed to the greater damage tolerance of the matrix. In composites with fibre glass cloth, the interlaminar toughness is also improved. An application of extreme value statistics showed that the change in resin toughness due to blending was fully transferred to the composite, and also allowed an estimation of the effect of the reinforcement on toughness.