A simple method to create self-organized patterns of microparticles in polymer films is demonstrated. Dye-loaded zeolite crystals are used as model microparticles, allowing convenient imaging of the patterns by fluorescence microscopy. The pattern formation can be interpreted within the general framework of the model of local self-activation and lateral inhibition. Two starting parameters, namely the polymer concentration and the wet film thickness, control the size and shape of the particle aggregates in the patterns, as well as their spacing. The size of the aggregates ranges from 50 to 340 pm. (C) 2011 Elsevier B.V. All rights reserved.