Macbook Air 13 inch screen keyboard marks

I have just bought a macbook air for college and as any person that has ever bought a expensive product i want to take good care of it so it would last me a good amount of time( at leat until i finish law school 🙂 ). After some research on the web it has come to my attention that the keyboard can scratch the screen when the laptop is in a full backpack (quite a typical scenario in a students life). Should I put a microfiber cloth between the keyboard and the screen when i close the laptop or should I invest in a screen protector or is my fear just stupid with no ground in reality ? Thank you in advance !