When you buy a brand new pair of Oaks, they always come with one (or sometimes two) of the arms covered with a plastic sleeve. I'm guessing this is to prevent one arm from rubbing the other during transport. Do anyone of you keep the plastic sleeve on when you store your glasses in the bag? I started to use two microfiber bags for one pair of glasses - one goes around one arm (like the plastic sleeve) and the shades go in the bag (to prevent one arm from rubbing the other. However, it's somewhat of a pain and I'm starting to think that perhaps this is not necessary or a waste of time. What do you all think?