Hello all, I just recently purchased the Late Oct 2013 15" Retina from the refurb store and had a question about the screen. The computer came with a very thin liner that was sandwiched between the keyboard and the screen. I presumed to keep the keys from scratching/marring the screen? Do you all continue to use this for protection? Do you use something else for protection? Do you not use anything and all is fine with no resulting marring or scratching of the screen? Just wondering as I'd like to keep the screen pristine for my viewing pleasure Thanks for any and all input!