REC CAST is a special material based on polymethyl methacrylate with the addition of special plasticizers. The material is prepared specifically for printing objects used in casting for burned models. In the development of this material, we conducted tests in the research center of Moscow State University. The results of thermogravimetric analysis in a dynamic air atmosphere showed that the mass fraction of ash is less than 0.01% of the mass of the printed object when it is burned to ~ 405 ° С. Thus, this material has an extremely low ash content, which makes it an ideal material for creating burn-out master models.