Ok, I am having a brain fart... help me out! (I've been told I have baby brain!)

If I dry out a fondant decoration/piece for a cake, after it is dry, if I pipe on it with buttercream, will that make it all soft again? Or will it hold up? I can't remember because I haven't done it in looooong a while, and the other day I just put some little BC dots on a fondant cut-out and it started to get soft, but it might have been because I put it in a ziplock for delivery and it got a little warm. (Humidity perhaps?) What about royal icing? This piece will not be eaten, so it doesn't even have to taste good! Hehehe.

Either icing has a small risk of softening the fodant. but closing it in a bag will really keep the moisture in, and certainly will make it soggy.

I would use royal, because it dries quickly. Still, don't close it in a container, just loosely cover it if needed.

That's what I thought. I mean, the fact that I put it in a bag helped make it soft. I just didn't want it to get dirty since it was going on the cake! Thanks for your input! It's appreciated!