I have one for my M1 and my M2.
That's the only good solution.I’ll wash my fingers more often.
I use a white sheet of paper and it’s perfect. No finger print on the screen. I also put a little dot to check which face to put.
I suspect this too. Of all the keyboards I’ve had or still have, the keys on my new 16” M1 show these shiny spots more than any other, no matter how old, and I only got it a couple months ago. I’m no OCD germophobe by any means, but I wash my hands enough and am not particularly oily/sweaty either. Something about this key finish or material is really oleomagnetic, to coin a term.The finish on the keyboard isn't the best. I would honestly recommend that you wash your hands before using it, and give it a good wipe once your done. Those grease marks are going to transfer to the screen, so be aware of that as well.
I know this is a very old post. I was looking for creative solutions to a similar problem. I recently purchased an iPad Pro with a nano-textured screen and an iPad Magic Keyboard.Yes, I put a sheet of paper on the screen when it’s close. I’ll wash my fingers more often.