4 hours ago, choc.frogs said:..also what I'm scared of. I'd overheat the edges and the cocoa butter design will melt/seep through as well. I've had this at times when I've loaded the mould with chocolate incorrectly (rather than the 90 angle held the mould at 45) and as it pours over in to other cavities the cocoa butter melts off the edges slightly. A mm or 2 but enough to be noticeable.
It's probably not CB melting from the edges (after all, you're capping with tempered chocolate that should not be hot enough to melt anything), but rather chocolate that has dripped or been forced into the tiny space created when the shell crystallizes and pulls away from the mold. Annoying when you spend so much time decorating, but it happens to most of us.