I've taken to doing my FBCT's thinner on the edge so I can mold the side down to the base level of frosting. I build up behind the image how ever much I want it to look "3D" as I'm making them. Then I have the wax paper folded over the sides of the cake board that I'm piping it onto to place it onto the cake to keep it from bending/cracking (since it's so much thinner than a traditional FBCT). I really like the puffy effect and it keeps the cake images cleaner IMO.