Dunno if it's vegetable tanned or not, but I use what Tandy leather shop calls "latigo." I think it's often used for saddles and tack. Very dark, quite thick, moulds well. All my CS knives ride in new sheathes, along with the Mora blades with remounted handles. (The plastic handled beaters from Mora live in the cheap, ugly, but effective black plastic tubes they come with.)