SWAROVSKI 2088, HEART HOTFIX FLAT BACK The Swarovski HEART shaped hotfix flat back crystals are as cute as can be! These beautiful elements are perfect for that special little something on your project. Use four together to create a 4-leaf clover! Used on clothing or craft projects you can't beat how versatile these crystals are. The HEART crystals feature Swarovski's unique heat sensitive adhesive which can be applied to your project using specialized hotfix tools, heat press machines or your household iron.