I bought this knife a few years ago, and after carrying for just a bit, it developed this kind of a hard film on the blade on both sides. I don't think it is rust, as I keep everything oiled very regularly, and while oiling today no rust came off when I whipped it down. The blade is Damascus and I was wondering if there is anything I can do to fix this? Thanks!
That's patina, you evidently cut something that reacted to the high carbon in the blade. The only way to get it completely off is sand it down with at least 600 grit sand paper and re-etch it. You can etch it with hot vinegar of you don't have any ferric chloride. If you get down to Burleson give me a heads up and I'll do it for you in a few minutes. Of course no charge, just send me a PM.