Hello Lydia, I am using Sylgard 184 too. But when I deposite a thin layer of aluminum using evaporation method, the Al layer I got also has some thin cracks. Maybe it is caused because of the temperature. Can you share the method how you make the aluminum layer without cracks and acting like a mast? Thank you! Best regards, Licca mi612738@ucf.edu 2005-01-19