In the last ICI Conference in 2011, we delivered a presentation about two newly developed synthetic ceramic materials designed to be used as investment casting shell replacing Zircon Sand and Flour. The first material was Synthetic Spherical Mullite Grains, or WING CEREADS, which is used as prime stucco, and the second material was Synthetic Mullite-Corundum Flour, or CASFILL-85, which is used as prime slurry. The heat-resistant capability of the materials was found to be unchanged from or better than that of Zircon Sand/Flour. The spherical shape of WING CERABEADS contributed to dense structure of prime stucco layers and CASFILL-85 was proven to bring little reaction between molten metal and shell. WING CERABEADS and CASFILL-85 were used in industrial trials where Aluminum, Carbon Steel and Stainless Steel castings were made and were proven to perform as good as Zircon Sand/Flour and bring even better shell collapsibility. This presentation is going to report on experiments we have conducted since the last Conference. In those experiments, we tested two types of newly developed Synthetic Spherical Mullite Grains and newly developed flour materials with higher alumina content than CASFILL-85. Through the trials, we confirmed that those newly developed stucco and flour work as good as Zircon stucco/flour and thus can be used as a replacing material for Zircon.