I watched this thing on the history channel about the worst jobs ever and there was an episode on tanning leather. It was rediculously hard and super smelly, IIRC. the hide has to sit in this chemical bath for like 3 days and then you have to scrape all the hair off the one side and the fat and nastiness off of the other side. Then, it has to sit in this bacteria filled (heated) bath for like a week to soften it up so that you'd want to sit on it. After that it's got to be rinsed like 5 times. Then you can finally dye it and do whatever with it. Alltogether it was like a 2 week process I think.