I use chrome tanned leather about ~3 ounces and line with cloth, canvas, or whatever suits my fancy. If I want to add tooling, I sew on a 5-7 ounce piece of vegtan with the tooled pattern I like. I came up with my own shapes/patterns, so I am not sure what the Tandy patterns call for. I use a lot of deer skin or garment type leather for purses because the women Ive made purses for all love how soft it is. Using the weights I mentioned, they purses keep their shape and don't flop around like a cloth, especially after they have all their stuff in there. The pockets and side gussets add some rigidity as well.