I put all my cakes on cakeboards before putting them on seperator plates.
I put the cake on a cardboard, then securely attach the cardboard to the plate with a blop of icing. The reason is two-fold.
One, when they cut the cake, you don't want them cutting or marring your plates with the knife. Two, when the wedding is over, is it easier for the client to remove the leftover cake when it's on a cardboard, and put it in a cake box, thus freeing your plastic separator plates for quick and fast return. If the cake is on the plate, then the client has to do a hunt-n-search for something to put the cake on.
Quote by @%username% on %date%
%body%