From my experience, I think it's important to keep the enamel very thin, then it shouldn't crack.  Also, you might want to anneal it very slowly. Audrey

Does anyone have success with Opalescent enamels, namely Thompsons lead-free 2061 Opal White.

I want to use it for my silver cloisonné insects wings, I really like the effect but have a devil of a time keeping it from cracking, even in flat, small partitioned areas. I've tried 2020 Silver flux as a base as described in the Glass on Metal article "Opalescent Enamel" 1994 vol 13 no 6 article By Woodrow Carpenter. As described in Thompsons Workshop Manual it has a high firing temp and one of the highest expansion rates for a Medium firing enamel. I had they same problem I mean challenge with Thompsons Leaded 835 White Opalescent and even with the Japanese  N.S.RF-1.

Chris