In an effort to deliver the slimmest and most sustainable wallet, Bellroy has come up with what they are calling their Nude Approach. By almost exclusively using vegetable tanned leather and thread - that means no unnecessary liners - and creating as little waste as possible, their Slim Sleeve has the most slender profile of all their bi-folds. Still it carries up to 12 cards and some folded bills, offering more than enough room for most.