Well, the thickness of the plaque, how long it is on the buttercream and how it is placed are all factors. Are you talking about a flat plaque completely on top of a cake or a stand-up with just the bottom edges touching?
The thing with royal icing decorations and fondant decorations, is they have to be well dried. Then placing them on as close to serving time as possible is a good idea.
You could put a barrier in between like you do with color flow items. A piece of plastic or raising it on marshmallows or thin cookies, anything to keep it from touching the buttercream will do the trick.
Usually, a well dried royal icing item that is not super thin, can be placed on buttercream.
Hugs Squirrelly
Well, the flowers, like roses. are usually thick and they will hold up. Just not such a great idea to refridgerate ahead of time. But the thicker the decorations, the better and they will hold up well. I find that with both fondant flowers and royal, that if the cake is decorated a few days ahead, the longer the decorations sit on the buttercream, the more risk for the breakdown. Seems to be worse if the cake is enclosed in plastic, but a lot depends on the thickness and how well dried the decorations were to begin with.
If you are into making really delicate lace piping work, like lace tips, lattice etc., these items are so fine and thin and fragile, that they are more at risk if left on too long.
Hugs Squirrelly
hey, why not bake a flat butter cookie in the shape and size of your plaque and then do the plaque (color flow work with the royal icing) directly on the cookie? you could then place it directly on your cake, and you'd have extra insurance against breakage.
Quote by @%username% on %date%
%body%