AbstractPreviously, it was found that organic glass material having no optical strain could be cast efficiently in a very short time by radiation‐induced cast polymerization of glass‐forming monomers. In this report, practical useful monomer systems having glass‐forming property and good physical properties were investigated. Several inner plasticized comonomer systems of excellent impact resistance were found which could be glassified and applied to radiation casting. These systems included butyl acrylate or hexanediol monoacrylate as inner plasticized component. Physical properties other than impact resistance were tested. The casting polymerization was studied, and it was found that polymers without optical strain could be obtained in a remarkably short