The main purpose of this study was to optimize the glaze formulation of a company that produces vitrified products. In this type of process, the chemical composition of the glaze has a critical effect on quality indicators such as coefficient of expansion, R value, and creeping value. The procedure used in this study included design, modeling, optimization, and confirmation steps. By the selection of desired ranges of multiple responses, the optimum glaze formula that minimizes the cost was determined by Derringer-Suich optimization. The verification results for the optimum glaze formula exhibited good agreement between the regression models and experimental measurements.