I am doing a cake next weekend and a few weeks ago I made a cake and had a problem with the fondant decorations staying where I put them on the sides of the cake. They were shifting/sliding, more so the larger pieces.
I am sure heat may have played a role a lil bit. IT will be around 80 degrees when I do this cake but it will be indoors A/C.
But I just don't think that heat was my only problem.

I used a BC Icing 1/2 butter, 1/2 crisco.

Should I use a different ratio of butter/shortening? (I really like the smoother texture & flavor of the butter).

Is there a "trick" to getting the fondant to stick better (It held on all night)???
Is gumpaste lighter in weight than the fondant? (I've never used gumpaste) but if so, do I use it the same way?

I am not opposed to using Bettercreme, I LOVE the flavor and texture. Is that an option instead? I've never tried to stick fondant to that.

Not quite sure where my problem was.

Any suggestions?
Much appreciated.

i use smbc which is all butter and haven't had anything move.
could your fondant decorations be to thick (and therefore heavy)?

gumpaste will dry much faster than fondant and will not be very palatable.

someone who works with crusting buttercream (that sounds like what you are using) hopefully will sign on and give your their thoughts on the best way to attach. this will give you a bump

diane