The material inhomogeneity effect can be used to greatly enhance the fracture toughness of intrinsically brittle materials. The main reason is that spatial variations of material properties, i.e. Young’s modulus E and yield stress σy, influence the magnitude and the direction of the crack driving force vector [1]. Many investigations have shown the effectiveness of soft interlayers to arrest cracks and improve the fracture toughness under uniaxial loading conditions [2]. However, such layered composites are not applicable for bi-axial tension loading, since the component would easily fracture along the soft interlayer. The topic of the current presentation is to investigate design concepts for new, tough composites that are able to sustain biaxial loading conditions. The idea is to find optimum arrangements of voids that are able to catch and trap all possible cracks that might originate from a free surface. In doing so, the void volume shall be as small as possible. Based on the configurational force concept, a computationally efficient crack trajectory interpolation method has been developed, which evaluates the trapping zone size of circular and elliptical voids in terms of the load biaxiality factor β [3,4]. The trapping zone is the area around a single void where approaching cracks run into the void and get trapped. The procedure has been extended to determine the trapping efficiency of arrays of voids. Void-particle combinations have been investigated, too. The improvements in fracture toughness are evaluated by a damage-based approach. Hereby, perfect and pre-damaged void surfaces are assumed. Practical applications are discussed, such as in additive manufacturing, where voids can be replaced by particles with low E and σy in order to facilitate the manufacturing.