Hi I'm interested in sculpting a 1:6 scale head. I'm not sure what product to use? I haven't done this kind of thing in years. I use to use Plasticine and I've worked with wax, but I'm sure there is something way better and easier to use.
If you want to make the kneeding easier get a cheap wood rolling pin and that way you can pound it and flatten it and it makes kneeding the older stuff easier. My super sculpty gets a bit dry with age and i use the rolling pin on it. Also helps with uniform thicknesses.
If the sculpey is hard then try to kneed a little bit at a time. When you are able to flatten out a larger piece use one of these pasta makers to run it thru a couple of times on diffrent settings.
Do not force it! use the biggest setting a couple of times before stepping down to smaller. I have broken a couple of these machines because i tried to force it when it still was "hard"ish
Get some Super Scupy Firm. It's grey. Mix it 50/50 with the regular. It'll give you good consistency for detail. Another hint: use pressure with your tools, rather than carving. Use a very light touch, and you'll get a feel for it.