The flat back rhinestones are widely used and perfect for apparel and cell phone. All of our rhinestones are only sold in original sealed-pack from Swarovski 10 gross (1440 stones) per pack for most sizes, 2.5 gross (360 stones) available for SS30 stones, 1 gross (144 stones) available for SS34/SS40 stones, 0.5 gross (72 stones) available for SS48 stones. Before Starting Crystallized your mix and match idea with Swarovski rhinestones, don't forget to prepare rhinestone supply: Bond Instant Grip, rhinestone picker and Swarovski crystal color chart (actual stones) to get a better idea about the colors before ordering.