Platinum-complex-loaded colloidal polystyrene particles are prepared by a miniemulsion technique and deposited on silica in hexagonally ordered monolayers. Optimized plasma and annealing procedures generate Pt particles with diameters appropriate to their metal content at interparticle distances given by the colloidal size. Serving as etching masks in a reactive-ion etching process, the original order of colloids is transferred to nanopillars and nanoholes with aspect ratios of up to 10 (see figure).