Flicker, thanks for explanation! Sometimes I ran into word combination that just doesn't make sense to me So, this weekend I will be trying. I am afraid to pour too hot, because it would melt the previous layer, wouldn't it? Also, I am using different types of bases: top is regular clear glycerin, and the bottom two layers are extra-hard opaque base. Extra hard is nothing like any other opaque bases I have tried. It is literally rock solid. Could that be a reason for popping layers? SherriLynn, I am making several batches this weekend. I am also going to do one tray at a time, instead of working with couple at a time. That way I can focus on temperatures, etc. I will post my results