Ultrathin films of small organic molecules are patterned with nanostructures, the size of which is controlled by adjusting intermolecular interactions. Nanowires of controllable widths form in the mixed Langmuir-Blodgett (LB) films of long-chain fatty acid and hybrid carboxylic acid (see figure). Templates, which can confine both organic and inorganic materials, are fabricated from three-component LB films, containing an amphiphilic silane-coupling agent.