When I was a kid I was awed at the finish of my grandfather's pocket knife blade. It was a dark luster with a damascus type finish. He told me he achieved this finish by sticking the blade in an ice potato for a couple of weeks. Well 35 years pass and I had just bought a Case Trapper knife with a carbon blades, the blades had a chrome finish, so I tried it. I stuck the main blade up to the handle in a large ice potato, placed it in the bottom of the fridge for two weeks. The chemicals in the potato did a marvelous job. After a little cleaning and a light coat of oil I have a knife just like my dear old grandpappy.