I have posted this a few times, so sorry for the repeat. But use rainx from any auto section of any store. It is for windshields, but clean your screen good than apply rainx 2-3coats letting it fog up and buff or wipe off in between each one. This will make your screen super smooth and it helps cleaning any prints off easier if you do get them. It does not effect your screen at all. worth every penny of the 4dollars. i usually need to apply once a month...2-3coats each time.
Thanks for the tip. I never thought about using rainx for the SP. Great idea, works very good. I use it on my car all the time.