I am planning on decorating a few styrofoam dummy cakes that I have and am wondering what to use as a fondant covering. In the past I used home made fondant and it hardened but slowly melted over time. What can I use that will last a long time?

For the dummies I make, I use the cheapest ready made fondant. Usually it's Wiltons brand. (purchased with their 40% coupon) Works great!

I use my MMF most of the time, unless I'm lazy - then Wilton. I've not had a problem with melting. But I live in a low humidity area where it is rarely hot. That may be the difference.