Macbook - Just bought a black iSkin protouch.

I love it! It looks great from far away, you can't even tell it's on, and I love the comfort of it, even though typing is slowed a little. I was just going to ask anyone else that has one of these, does it harm the screen at all to close it with this thing on? Will it smudge it or anything? Obviously I bought this to protect my mac and I don't want to make the screen worse by protecting the keyboard.