if I make cutouts from fondant to attach to a cake next week will they harden or do I need to add something to them to make them harden? I want to make a clothesline cake for a baby shower and I want to make the clothes this weekend if I can. I have never worked with fondant before so I am not sure... thanks

yes they will harden, I usually have a hard time working with fondant, because it dries out toooooo fast. Depending on the thickness, it becomes very breakable when it's dry!

To keep it from hardening so quick wrap your pieces in plastic wrap, then into an air-tight container which can be stored in the frig or fzr.

Your clothes line pieces are very small - it really won't matter that much if they do dry out. If the piece was large it would not conform to the roundness of the sides of a cake unless you dried it on something w/the same roundness.