When I sharpen a knife, as I have learned here from all you great fellas, I either put blue painters tape on the blade where it will sit in the vise or if it is a full flat grind, I use a drawer liner material to make up the difference. And when I move to the next stone in order, I use a paper towel sprayed with a small bit of alcohol, to clean the blade for the next grit. And while doing this, I guess the alcohol has gotten on top of and beneath the tape, and once I finish with the sharpening and pull all the tape off, you can still see where the tape was before. Like it has stained the metal. This is both on satin and acid wash blades. I’ve rubbed them with the same alcohol trying to clean it off, but at just the right angle under the right light, you can still see where the tape used to be. Any of you guys have any suggestions?