AHi im new here and new to cake decorating. I apologise if my question has asked or is in the wrong spot. I madesome decorations for my cake about 4 days in advance. I used fondant with cmc powder. They took a few day to go hard ( although not completely) then went soft. I thought i may not have used enough cmc so the second time i used more cmc then hardened up quicker but i decided not to use them on my cake and the next day after party they were completly soft again. Did i not use enough cmc...althought i thought i used alot more. How am i supposed to store decorations? I just left them out in the air to dry. How long are they supposed to stay hard for?. I made flowers and stars on wires and spirals that i wraped around a pen for shape. What did i do wrong? Thanks.

A typical recipe is 2 teaspoons CMC/tylose to 1 lb fondant. A big flat piece rolled out, say, a 6 inch star,  get's hard enough to stand up attached to a lollipop stick within hours and definitely over night.  Unless you put it in the frig, then it will usually get softer. If you live on the beach or something, you may need special tips for that. But I live in Houston, which is more humid than most places.
 

AWe have had cooler weather the last few weeks (adelaide australia) maybe about 15 20 degC. And cooler overnight....could this temp have something to do with it? (Beach is far away)