Wide particle size distribution (PSD) of carbon black increases electrical conductivity, consistent with the industrial practice of manufacturing conductive grades. An explanation has been offered based on the lower linear average diameter of wider-distribution blacks. Consequently, for the same weight, there is a larger number of particles in the broad-PSD black. The resulting agglomerates are therefore more numerous, although somewhat reduced in dimension because of higher packing density. The larger number of agglomerates results in lower average gap width, which accounts for the increased electrical conductivity.