or any good tecnique to make mold
If you're making a mold you probably don't want to use soft clay. If the clay you use for the model is harder it will hold it's shape much better when you create the mold. As far as a substitute for Klean Klay most (including myself) tend to use Chavant NSP. It's a really nice clay to work with. Another you can try is called Sculptex from Reynolds Advanced Materials, which is effectively the same as both Chavant NSP and Klean Klay. Sculptex can be found here: http://www.reynoldsam.com/product/sculptex/ and Chavant NSP is relatively common and easy to find, but here is an Amazon link nonetheless: http://www.amazon.com/Chavant-Clay-Medium-Sculpting-Modeling/dp/B00...
PS keep in mind when comparing prices, Sculptex is listed by pound, and most listings online for Chavant are by 1/4, 1/2, or full case.
I use this alternative, and it's perfect! Van Aken Klean Klay Alternative
It gets softer the more you work with it, so you can mash some softer bits into the hard to reach places, and it hardens a bit when left alone, so you can easily smooth it out to a nice clean surface. If you've worked with Van Aken before this is very close.
Puppet Putty is harder and less greasy than all of those. Lighter weight, too...
I tried Klean Klay for sculpting, and this is what I found: Because it was soft, even the "firm" is softer than my other clays, it was very quick to rough out the basic shape. But then I couldn't get the finer details or perfectly smooth surface, I needed something a bit harder. I replaced the head and hands with harder clay, but tried to stay with the Klean Klay body, and it took me much longer to finish it, and it wasn't quite as good as if I'd used a firmer clay for the whole thing. So now I only use the KK for making clay walls for dividing the mould.
Chavant NSP (Non Sulphur Plasticine) medium grade is a pretty good one for sculpting and making a mould from, if you are going to cast in a platinum cure silicone like Dragonskin or Platsil Gel-10. (Those silicones don't cure if a clay containing sulphur was used for the sculpt.) I warm it a bit beforehand so it's softer when I am starting, and easier to shape, then as it cools it gets firmer and takes detail better. Bits can be worked in your hands to warm and soften them as you go, when you want to add a bit of clay.
Chavant NSP Hard is much harder, you have to get it fairly hot, enough for it to be a little uncomfortable to touch, to make it soft enough to rough out the basic shape of the puppet. You can do really good detail work by carving it, but it doesn't warm in your hands enough to make it workable like the Medium does. I found it too difficult to work with for most things. But for one of those trues scale 1:6 action figure heads like you can buy of well known actors or historical figures, you would need something this hard. For my bigger heads, more like 1:5 scale, the Medium worked best.
This video shows some Chavant NSP Medium being used to sculpt a head, then the mould being made in a hard plaster (Hydrostone) and the puppet getting cast in silicone:
Art Molds sent me a box of Chavant samples awhile back. What all of their clay had in common is that it was fairly brittle. I still have the samples, which have not improved in consistency in the two years since they were opened. Once warmed in the hands the clay does become softer, but it still breaks apart easily. It does not stick to tools terribly, so it is good for general modeling.
Pretty much any non-sulfur clay should work for mold making. I'm not sure why such a big deal has been made about the particulars of clay needed for that purpose. This question has come up tens of times on all three incarnations of this messageboard from 2001 to 2015, despite being only a Google search away for most of those years. There are a good many wax-based brands that work with silicone molds and are inexpensive. In the 20+ years I've been around clay (whether testing it for companies, animating with it, or creating it from scratch, I have only encountered a few brands that had sulfur in them, and they weren't easy to find. One was Roma Plastilina (came in a gray-green color from a college campus art store) and another was made by Amaco. Sulfur-based clay tends to be very greasy and has a different feel to it than wax-based clay. It also has a distinctive smell to it.
Roma Plastilina is not designed to melt, and tends to be pretty hard and dusty. Not sure about Jolly King. Because a great deal of heat is required to actually melt sulfur, the temperature required would be far above the peak temperature of a double boiler, limiting the number of formulas for sulfur-based clay that could be melted. This is a good general guideline when determining whether or not your clay contains sulfur: it will become sandy-looking when you attempt to melt or overcook it and it will give off a smell. As most sulfur-based clays tend to be only available to industrial designers for sculpting car prototype models, you are not likely to see them on retail shelves. That is another good indicator when shopping for sulfur-free clay. Because sulfur is yellow, it will also throw the color of its tint off somewhat. Sulfur-containing clay generally does not come in bright colors and is extremely smooth-almost slick- to the touch. You'll know it when you see it.
We're working on that, Nick.The last thing we would want is for our shipping to be landlocked. Thankfully we have our clay book for anyone who can't get the product. It's not going to be exactly the same thing, but it's better than nothing. I'm glad there are other clay manufacturers out there, and don't mean to come off sounding like I wanted everyone to only buy our clay. It's a niche product that serves a niche customer and we're already struggling with building up inventory fast enough to meet demand. The shipping in the U.S. is flat rate, so people aren't buying one or two packs at a time- they're buying 10 or 20. That depletes what we have on hand pretty fast. Surprisingly, our biggest order so far came from Australia.
There are several hardnesses of Roma and I think I got the wrong one that time (No. 2 White). The gray-green from the art college was very soft and must have been a #1 hardness. So we can probably "chalk" that up to user error. ;)
My Roma is not hard or dusty, not when I first bought it new from an art supply store in LA (near Universal Studios), and not now, 20 years later, after using and re-using it hundreds of times. Actually it is a little soft. But I had to go to a non- sulphur clay once I started working with silicone.
Monster Clay is another one, quite waxy, which softens nicely when warmed in your hands, but gets quite firm when it cools.
The main thing stopping me from trying Don's clay is the shipping costs to Australia, but also I have large amounts of other clays for sculpting anyway and will probably never need to buy more for the remainder of my puppetmaking life.