he explained it to me, but it was like a 5 step process.... he first stretched the leather for like a day, then used some kind automotive epoxy/bonding used in custom car upholstery, then bee's wax for something (which it still smells sweet of), then some kind of sealant wax.... the seem in the back is clean. like i said, i was floored when he broke it out, so i didn't absorb to many details.