To avoid "slump" in figures, you have a few options. One is to prop them up while they are baking. Another is to have a armature (wire, aluminum foil, etc) underneath the clay to hold it up in the oven.
If you go for proping her up, I personally use cornstarch, I pour a big pile of corn starch in the bottom of the pan, lay the item I am baking in it. Then I will usually flip it and bake the other side, as the side in the corn starch will not heat evenly, and I want to make sure the whole thing is cured, if you do not throughly bake your polymer clay, it will crack and crumble as time goes by.
If you are using the big grey box of super sculpy, it is more likely to slump while cooking than the colored stuff.
should honestly build some type of base with support with a decent armature...for it to last.....R u using the pink super sculpey?? put it on a baking sheet or something. Read the back of the box for baking temps. For super sculpey bake it at no more then @ 275*F for 15mins......i usually bake mine at a slightly lower temp for a little longer(like 225 for 20mins)....if you own a heat gun you can use that also to bake it. Your just baking it way to high.
IF the sculpture is in the oven, i like to touch it to see how hard its getting, when its like half way between being soft and hard. I pull it out of the oven and let it cool down. the cooling down process still lets it back for a bit...i like doing it this way so it doesnt get too baked for a very long time and then will crack easier. If you over bake it ,it could melt...or dry to hard and crack. Finding the happy middle is good.
Actually, while you can bake polymer clay at took hot a temp, and bake it too short a time, you can forget it in the oven overnight and it will be ok (unless you are using translucent, which will darken over that amount of time) I know this one from repeated experience.
Well, the one I made before had some foil armature, but these are barely 2 inches tall. And the foil didn't really help with the flattening problem; hoewver, I think I will try the scrunched up foil! Although, do you think wax paper could prevent browning ?
Try giving your next figurine a skeleton made from wire and foil. Use the wire to build up her appendages and scrunched up aluminum foil to build up her basic shape. It will help preserve her structural integrity, and you won't need to use as much sculpy. Just remember that the sculpy layer is now thinner, thanks to the skeleton, so don't cook her for as long. Secondly, remember that foil will trap air inside the sculpture, so leave some minute holes in her so that the hot air can expand and escape, otherwise the pressure may crack the sculpy.