I actually do black cloth by starting at charadon granite with a bit of black mixed in. from that base I add more black to shade the folds, and vmc iraqi sand to lighten it up for highlights. You have to play with it a bit to keep it subtle, otherwise you end up with it just looking like a weird grey-green, but once you get the method down, it comes out pretty good.
iraqi sand....that's racist!
Wargamescon 40k Judge
caldera40k.blogspot.com
Hogleg - "only in my head someone bought CRP's OOP Wraithlord then stuck its toe in cover."