Pockmarks/pits in aluminum body of Macbook Pro

I noticed there are little black pits scattered across the bottom aluminum covering of my Macbook Pro. I have never used cleaners on the body of my mac, and I have had a clear hard plastic case on it ever since I got it. I have a mid 2014 13-inch Macbook Pro with retina display. Any ideas on what's causing this?

I attached pictures: one is zoomed in a little more to show details. And for reference, the pits are not bigger than ~1mm in diameter. Thanks.

Welcome to our forums.

The marks appear to be caused by corrosion which can occur if you used a case and moisture got between the case and the aluminum body. Putting any kind of case on a Mac with an aluminum body is fine as long as you remove the case occasionally - like when you use the machine at home. I'm not sure how you can remove those marks. Perhaps someone else may know.

I agree; and have this to add:

Apple designates MacBooks as Notebooks - not Laptops. They are meant to be used on a flat surface, like a table, because the vented hot air is downwards. Not rested on a lap, not on a cushion and never on bedclothes.

Not saying this applies to you, but the point is that vented hot air could get trapped between the case and the body where it would condense on the Aluminium surface - as Admin chscag said.

Whilst Aluminium is said to be corrosion resistant, it's probably an alloy on the MacBook.

Ian

If you want to try to remove the spots, I would suggest some automobile polishing compound. Get the one with the finest texture, probably one made for the final polishing. Use it gently and sparingly.

Thanks for the help. I guess I didn't know that I should have been taking the case off to let it breath. It makes sense though.