When these sheets first arrived they were exactly what we were expecting and we were very satisfied.  We followed all general instructions on proper washing and care for sheets of this material and thread count and they were fantastic for the first few months.  Then, seemingly out of nowhere, the fitted sheet started to pill as bad as a cheap cotton or flannel sheet.  The flat sheet and pillow cases never suffered from this problem but unfortunately the fitted sheet became nearly unusable.  Definitely not what we were expecting for the price and considering that quality sheets like this can last for decades.  Now the fitted sheet is being used to cover a box spring under a mattress simply for aesthetic purposes.  Very disappointing.