Are you sure that Sculpey has to be only a 1/2 inch thick? I'm only asking because I made a cake topper for our wedding cake (my husband holding me over his head). I just molded the figures (he was about six inches tall, me about five) and baked. Presto.
(the only bad thing was we had ice cream cake at our reception. It was starting to melt a bit, and the topper fell off and broke off my head. I was afraid it was an omen. :^0 )

Whoa, sorry about your head!

You might be right, redvixen. I'd bet Sculpey and Fimo bake best at 1/2 inch or less, but just require a little more care or attention at thicker... thicknesses. Products always tell you the optimal conditions for use so that, if you do anything else, you can't blame them if it doesn't work out perfectly.

If your cake toppers were 5" and 6", their thicknesses must have been better than 1/2".

Thanks! Expirenmentation is needed...

Come to think of it, ages ago I made a holder for a beard trimmer (so it would stand upright in the medicine cabinet) that is over 1" thick all around, and it baked fine and lost none of its detail or even texture.

And I ocasionally buy or peruse Spectrum (a fantasy art yearly periodical) and there are always some gorgeous Sculpey works that you can tell had nothing but a crude wire armiture under some often very thick clay...