Linen is the natural moisture wicking fiber. These fibers are tube shaped which moves moisture away from your body so you stay dry. These duvet sets cover your synthetic or natural filled comforter (purchased separately) and provide a machine washable and natural fiber cover. The shams included in the set feature a fold enclosure. The duvet includes corner ties and features a button closure. Comforter insert is not included and must be purchased separately. You can rest assured this program is made responsibly with OEKO-TEX Standard 100 Certification with certificate 14.HIN.38767 as certified by Hohenstein.