BedCare Organic All-Cotton Pillow Covers are made of unbleached 100% GOTS (Global Organic Textile Standard) Certified Organic Cotton so you know you have the very best quality available. With a pore size of just 4.8 microns, only air can permeate this tightly woven fabric, for total protection from dust mite allergen and bed bugs while you sleep. The quality of these zippered pillow covers is guaranteed because of the care American craftsmen put into each and every one. Even the most discriminating cotton lovers will be delighted with Organic All-Cotton pillow encasings. Machine wash and dry.