Ah, you're talking about an air-dry clay? A friendly word of advice - on this site or any serious hobbyist site, you need to be fairly specific with terminology - a word like clay can mean so many different things. But from what you wrote it does become clear what you mean.
That actually sounds like it might work pretty well. I'm not sure, I've never tried it myself, but I do know that latex will cure when spread on plasticene. In order to get your original clay sculpt out of the olasticene mold you'll need to slice the mold opendown the middle (or maybe into three or more pieces depending onthe sculpt's complexity) and sort of peel it apart - but that will actually make it easier to put latex on it - don't try to form ot back into the actual shape of the head, just peel it open and latex it up. Then make pieces of latex skin that you can glue onto the armature. See if you can get some flexible contact cement, which is great for gluing rubber to things (including itself). After opening up the plasticene mold I'd add a little rim of plasticene all the way around the edge of each piece so you'll get an extra little lip of latex skin - that will make it easy to slightly overlap the edges skin pieces on your armature and glue them together. Of course on any part that's going to overlap another you'll trim off the extra edge so all that shows on the surface is textured latex skin.
Have you looked at any tutorials on how to sculpt textures like dinosaur skin? I'll see if I can dig some up. Also look at tuts on making plaster molds - it's not hard to do and is a very basic skill you'll use for just about everything in the future.
Yeah air drying clay. Sorry
Angus, you might want to take a look at this - something very interesting I found in the Photos section: http://www.stopmotionanimation.com/photo/harpya-3?commentId=6519681...
Daniel Svensson made his molds from plasticene apparently. As soon as he said that I thought about this thread and had to post it here.
Your main rule when casting/making moulds:
SOFT MODELS GO IN HARD MOULDS, HARD MODELS GET CAST WITH SOFT MOULDS
So if you want to cast latex: you go soft model, hard mould, soft cast.
If you want to cast something like resin: you go hard model, soft mould (silicone, plastacine, even sand works), hard cast.
Your suggestion may go alright, I don't know, but I would seriously disencourage making a model with paperclay and then the mould with plastacine. either make the model with sculpey and bake it, then do plastacine, or make the model out of plastacine/paper clay and cast in plaster.
Plaster is dead easy to cast with, and you can buy ready-mixed pots (or only need to add water) at most DIY stores. and it's el cheapo.
Also making a model with paperclay is a pain in the ass, and what I likely see to happen is that it will flake off into the plastacine when you try to pull it off - ruining your soft mould.
I made a similar mistake once the other way around: hard on hard
It took me two days to remove the sculpey out of 4 moulds and by that time the moulds were damaged and my hands were cut to pieces. I even slice the top of my thumb and cut my FOREHEAD as the knife broke and shot up (could have been my eye!!)
Anyways, TLDR; Don't do it. Get plaster. Make your life easy (it is the easiest method of casting a mould already).
I used to sculpt my heads in plasticine clay, and then coat the finished piece with several layers of liquid latex. This creates a latex mold of the clay original. Remove the clay, and pour in mixed plaster. Just hold the mold upside down in your hand as the plaster hardens. I have used the bottom half of a milk carton with some sand in the bottom to hold the mold as well. When the plaster stars to harden, insert the neck wires into the wet plaster. Once the plaster hardens, gently peel off the latex mold. You now have a very detailed plaster head, ready to be attached to your armature. This method is of course best suited for a non speaking character, but the results look fantastic.
I don't really see how the the original solution is easier. I've been making 2-part plaster molds since high school, starting out with Plaster of Paris. That was over 30 years ago before the internet, and if a dumb high school student in rural Indiana can handle it then anyone can.
Yeah, making plaster molds is a very basic skill that isn't hard to learn at all. I should have said that right off the bat. Stopmotion requires a great deal of problem solving and a set of skills - working with plaster is one of the simplest skills, and once you learn it there's a lot you can use it for.