Barge contact cement which you can get at Tandy's Leather...hideously expensive. Choice 2: Wildwood contact cement made by DAP which you can get at Home Depot much cheaper...drawback, you need to do a thin coat on each piece and let it almost dry, same as Barge but to get it to adhere really well you should do that twice before sticking your pieces together but it does work and is much cheaper and easier to find. Third choice, hot glue.