I am in the process of making an autumn cake. I've already read up on how to make fondant pumpkins and apples. My fiance is a wizard at sculpting, but is very, very new at sugar art. We learned the hard way that some fondants are not equal to others and some beautiful numbers he created for a birthday cake couldn't be used because they wouldn't harden after a whole week and a half.
Anyway, I've tried looking it up. I'm pretty good about trying to find an answer myself, but I'm still not entirely sure - what would be the best medium to make a tree? It's going to be a naked tree with gnarled and twisted branches. 3D as my cake topper, not flat. I was thinking modeling chocolate because it's already a nice dark brown, but I'm worried that it might be too soft. Can you mix it with gumpaste? Or should I just use gumpaste?
Or am I better off making a batch of chocolate fondant and mixing it 50/50 gumpaste?
Any help would be appreciated. I plan on cracking the whip at him and making him do it this weekend

I have never used modelling choc, but think that would be fun to try. However,I usually use fondant with gumtex/tylose powder because you avoid cracks and it dries hard. But for the tree I did last year, I used gumpaste for the base and rubbed on choc, then made the leaves out of grape stems dipped in choc melts. The trees turned out exactly the way I hoped (though the tank cake didn't)! I like to make everything edible and technically it is....I got the idea here. Not sure if it's the look you are going for, but here it is:
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1497201

HTH!

Modelling chocolate is perfect on it's own, I don't know what would happen if you added gumpaste to it. I have tried making tress with fondant, gumpaste, 1/2 and 1/2 and I prefer modelling chocolate hands down!!! I have made tress this way and piped on leaves made with candy melts, and i have left them bare for that spooky fall effect. Good luck!

I'm leaning towards modeling chocolate at this point. I've seen quite a few neat videos on it and we have no issues with heat or humidity. My biggest concerns are becoming too soft to work with too quickly and I've also read about a problem with greasiness. I plan on using semisweet chocolate chips and not the candy melts. It will be interesting - and I'm buying a bag of powdered sugar too, in case I end up getting frustrated and need to whip up a batch of fondant!