AbstractAt ILE, Osaka University, the development of large shells for a future laser fusion reactor and the improvement of the characterization technique for plastic shells used in current implosion experiments with the GEKKO XII laser system have been conducted. In the former, large polystyrene shells with 30–150-μm walls have been successfully fabricated using the conventional emulsion method. Our experimental results indicate that there is some centering force by which a non-uniform emulsion becomes uniform during the solidification process in the emulsion method. A model for this centering force is presented.