Hi sleepypeepy,
I would agree wholeheartedly with dn’s comments 
There is more information about different types of sheets in post #7 here and the posts and webpages it links to (including a couple of threads that discuss linen sheets).
I would also agree that a mattress protector used in between your sheets and bedding is also a very good idea to protect the mattress from moisture, body fluids, and skin cells (which can feed dust mites) and to protect against accidental spills (and protect your warranty). There is more about the pros and cons of different types of protectors in post #89 here.
Phoenix