The air-dried clay doesn't need an oven to hardens. Instead it just hardens by exposing
it to the air after it's been conditioned.
One brand I've used in the past is Darwi. You conditioning it by adding some
water to it and knead it thouroughly. After that, you've got approximately an hour
and a half before it's not workable anymore.
I found it quite hard to use because the type I had (there are a few different Darwi clays
around) didn't have a very fine grain so I couldn't bring the details that I wanted into
the model. Furthermore, after adding water it's a rather messy clay.
For larger sculpures it's really great because you don't need a big oven and
it isn't a really expensive clay.
|Hardens on air, great for larger sculptures
||Not for small details
|Quite cheap clay
Round about 2002, I discovered a new brand: Formofit.
It's easier to use as Darwi, and you don't need to knead it before using it.
And you need only a little water to let it stick to another surface.
It's still a very soft type of clay, too soft to create really small details
in a model, but good enough for most uses. It's not as cheap as Darwi, but
certainly worth the extra money.
|Hardens on air
||Not for very small details
|Not as expensive as Fimo/Premo
|Ready to use