International refiners make it convenient for investors to own bullion by offering platinum bars in a variety of weights and sizes. Purchasing platinum bars is a cost-efficient means of owning platinum. Bars bearing the “hallmark” (logo) of the highly recognized refiners are the safest way to purchase. These refiners “assay” or test the metal for its purity or fineness. The bars are generally stamped .995 (99.5% pure platinum) or higher purity, along with the individual bar’s weight. The top refiners are Johnson Matthey, and Englehard.