When you add you an enamel jewel to a setting the enamel against the metal has a very tinny sound. I have heard of some artist adding sawdust or plastic to get rid of this sound but here is a product Tuff Break, that not only eliminates the sound but adds setting qualities.
When you are putting pressure on the bezel to secure the enamel jewel in place, while closing the bezel I have had the enamel chip or crack around the edges. Tuff Break gives the enamel jewel some cushion as you place press on the bezel, minimizing the pressure on the delicate glass edge.
Check out my demo on setting enamels with Tuff Break.