I don't know a lot about the actual tanning process, but they are a by-product of the food industry and they are definitely polished before the final cleaning process. Watch bands are available, but you have to be sure to get the right mm size to fit your individual watch. You can get some idea of retail cost by doing a google search for the bands.....then when you shop you have some idea of price.....but remember not all ray skins are created equal (as to the finishing process) and the quality of the final product (sizing, stitching, lining, clasp) varies greatly.