Swarovski No Hotfix Flat Backs are loose crystal elements backed with platinum foiling for extra brilliance and protection. Yellow Opal is both fiery and elegantly matte, combining the power of color with genuine gemstone appeal. This crystal color lends a cool edge to modern casual looks and brings a brightness to glamorous statement jewelry. Yellow Opal is a natural pairing for colorful summer designs and sport chic creations. These Flat Backs are easy to apply to a variety of materials using standard one or two component glues, or design with style using Swarovski Ceralun Epoxy Clay.