Ortho White S Ortho white is a brilliant white stone manufactured from carefully handpicked and beneficiated mineral gypsum of highest purity, calcined under controlled conditions. Meticulous removals of all impurities produce this brilliant white coloured stone. This material is specially made for casting of orthodontic models and demonstration models. Optimum working properties and good surface hardness make this product a choice for the specialized application areas in orthodontics. Like our all other Type- III stones this material also have the same desirable handling properties, is engineered to produce rapid strength gain and easy release, permitting short processing time.