Looking at several bars last night that were stamped earlier in the day, I have concluded that the citrus eo has just changed the color. The mica is still there but the color is not. All the other bars that I stamped are just fine. Some thing to be said about the learning curve! For those who stamp is there a better way than using a fine paint brush for appling the mica to the stamp? I had heard of using glycerine but that was a mistake! For those of you that feel successful using stamps would you share pointers, please? Thanks, Linda