Gold Star - 21 Specifically developed to meet exacting requirements of gold and silver casters Permeable investment powder. Suitable for vacuum assisted casting High quality surface finish and detail reproduction Fast firing capability. Goldstar - XL Premium quality investment powder. Excellent surface finish and detail reproduction. Easy to clean off after casting. Fast firing capability. Suitable for centrifugal and vacuum assisted casting. Suitable for gold and silver casting. Goldstar - XXX A Premium investment powder developed recently. The very fine and soft investment powder not only gives a good surface finish, but also ensures that the investment mixing process is an enjoyable one. Accurate reproduction of very fine detail. Easy clean off. Suitable for gold and silver.