I've been experimenting with different recipes for making figures and sculptural type things for my cakes. I've tried using straight MMF--on the larger pieces it tends to slump. I tried adding gum tek, but seemed to make it crumbly. I also tried the recipe here on CC that uses a lot of cornstarch. I liked that recipe but it also tended to get crumbly as you worked with it. It is "ligher" than the MMF, though, which seemed to help with the slumping. So far, Wilton rolled fondant with gum tek added seems to give me the best results. Wilton gum paste works pretty well too, but it's just so darn expensive when you're doing the bigger figures. You don't use that much for flowers, but it's goes through pretty fast when it's figure pieces. I was wondering what some of you have had the most success with. I would like to find make it myself recipes as I don't live very close to any suppliers, but if I find something really good with reasonable price, I'll just stock up.
I use either Toba's fondant or the fondant for sculpting (actually it's pastillage) recipe on this site. I have also mixed them quite succesfully, more or less pastillage depending on how fast I want it to dry. I've never tried gum tex or any other hardnner so I dont know how it compares but I don't have any crumbling problems.