My case for the Zero W had a protective layer on the black bottom but the top seems to be finished in a matte white.
I have picked at it with excellent fingernails from all edges and angles on both sides.
So something else must be required. I am a carpenter and tool guy.
1. I have lots of sandpaper up to 5000 grit wet/dry. But if that’s a wrong fix, that mar the product.
2. Or should I use a solvent (maybe acetone)? Easy to imagine this might cause problems.
This isn’t a big deal for me, but I think there must be others with the same problem.