Hey guys, I’m new to knifemaking and recently finished my 2nd knife. I used Apple cider vinegar to force a dark grey patina but the sheath gave it these horrible scratches which took off the patina. Here’s the full process, please let me know what improvements I should make- After heat treat and cleaning up the bevel I hand sanded the entire surface to 220. Suspended the knife in a PVC pipe of ACV and let soak for 45 mins. Pulled out, sprayed with windex and wiped clean. I did forget to tape the blade before molding the kydex, not sure if that would have any effect. Of all the threads I’ve found no one has said anything about a forced patina rubbing/scraping off with only a few times in/out of the sheath.