I made marshmallow fondant ,double wrapped in plastic wrap then placed in a ziploc bag and stored in the refridgerator as directed. A week later i colored the fondant , rolled it out ( it was beautiful to work with) covered my cake and within a hour it was sweating , sticky and sagging! It eventually firmed up after a couple hours of having a fan blow in it.
Another time i was covering a wood shoe mold for a boot cake and the same thing happened. by the morning the fondant was sagging and looked like it was dripping on the bottom! Help