To prepare the rust, i need some pigments (Windsor & Newton) as well as '"leather'" coloured paint + black. I use Vallejo. I also need the top of a DVD case, why? because when you mix your pigments you tend to blow a biot of air here and there, and the borders are here to help you not to tint your working surface. the colours are: yellow, red, van dyk brown, black, sienna and burnt sienna. i try at each diorama not to use the same ratio -sop this time i went high with sienna and Van Dyk Brown + quite a bit of red for the highlights.