Hi Gasant-

There's a number of ways to do this-! depends on what you're doing with the pieces really-

The BEST stuff is called HardKote- Which is available here- http://www.flints.co.uk/acatalog/Pai...Hard_Kote.html

its good stuff and I've used a fair bit of it before, it can be watered down a bit to make it go further and looks like a slightly rendered sandy finish-

i used it on this-



and was fairly hard wearing apart from the kids poking pens into it...

or theres foamcoat which is smoother-

for a cheap alternative, you can scrim it so like papier mache but with muslin, with loads of pva to create a shell, the paint and seal with a good waterprrofing varnish/ glaze-

gimme a shout of you need any more help/ pointers.

George