100% cotton percale weave makes these duvet covers super cool and crisp. All Riley duvet covers have ties sewn into the corners that attach to the loops on our comforters so your comforter doesn’t slide around inside your duvet cover. Button closures at the end of the duvet cover securely contains your comforter inside, while allowing for easy removal for washing. Our bedding is Certified STANDARD 100 by OEKO-TEX® #18.HUS.35124 by Hohenstein - which means our source materials are tested for harmful chemicals and substances. We adhere to the highest standards to protect you and the environment.