In the investment casting process, molten metal is poured into hot molds, allowing for the production of castings with extremely thin sections, knife edges and sharp detail. This article discusses patternmaking and dimensioning, as well as the pattern materials, such as waxes and plastics, for investment casting. It describes the mold refractories, binders, slurry formulation, slurry preparation, cluster preparation, and coating and drying for the manufacture of ceramic shell molds. The article reviews postcasting operations, including knockout, cutoff, core removal, heat treatment, and abrasive cleaning. It discusses the design considerations for investment castings and tabulates common investment casting defects. The article concludes with information on the design examples in investment casting.