I purchaced some really nice 600 TC wamsuta sheets not long ago. They were quite expensive...around $300.00 but I got them on sale. Problem is the bottom sheet on my DH's side is pilling pretty badly. I'm very careful to wash them in warm...not hot water on gentle, and I don't over dry them. I can't figure out why they are doing this. When you run your hand over the sheet it feels like sand on them, but it's pilling.Anyone know what causes this? They are pima cotton, I thought they'd stay nice for quite awhile...they've only been laundered about 4-5 times (once a week) I can't return them as I bought them in a different state and don't have a BB&B here.