We observe that gold atoms deposited by physical vapor deposition onto few-layer graphenes condense upon annealing to form nanoparticles with an average diameter that is determined by the graphene film thickness. The data are well described by a theoretical model in which the electrostatic interactions arising from charge transfer between the graphene and the gold particle limit the size of the growing nanoparticles. The model predicts a nanoparticle size distribution characterized by a mean diameter D that follows a D proportional, variant m(1/3) scaling law where m is the number of carbon layers in the few-layer graphene film.