I was just looking at my latest blade on a real final kinda bit of shaping, and there was something that looked “off” about it. I couldn’t measure anything tangible, but when I looked at it under bright light, it was kind of weird. I decided I would polish up my mirror super good and inspect it with that. Yep, now that I could see both sides I noticed they were subtly different in one area. I’ve found mirrors to be an incredibly useful thing in the shop. Get some welding ones with magnetic bases. Keep one by your grinder, you can watch the “back” side of your blade when you are doing tricky grinds. Magnifying ones like for shaving are great when using magnifying glasses. You can OCD to a whole new level, lol. That’s all I know about mirrors. And yeah, sometimes it takes a special mindset to think of stuff like this. And that’s all I have to say about that.