I prefer to use "pigskin" or "calf hide" and place the pieces back to back so the smooth sides are both facing out. The pigskin is very light and durable and comes in a variety of colors. The calf hide is a bit thicker so I very the holster leather pending oz. of the calf hide used for the lining. I typically use 8 - 10 oz. for holsters with pigskin, and 6 - 8 with calf. You can use glues to help when molding holsters and liners, but I don't care for the way my machines operate going thru the glues.