Dispersions of nanoparticles in a resin component are described. The nanoparticles have a multimodal particle size distribution including at least a first mode and a second mode. The number average particle diameter of the particles in the first mode is greater than the number average particle size distribution in the second mode. The use of multimodal nanoparticle size distributions and the relative number of particles in the first and second mode to reduce or eliminate particle stacking behavior is also described.