Swarovski Flat Backs NHF are loose flat back crystals with no hotfix. They're the perfect crystals to use on a flat surface. Glue these crystal rhinestones onto jewelry blanks, shoes, phones, electronic devices, and a whole lot more! We recommend gluing with two-part epoxies for the best results. Choose from several colors of flat backs in an assortment of shapes, and get wholesale prices when you buy in bulk.