55% European flax, 45% organic cotton. STANDARD 100 by OEKO-TEX® certified: Tested in a third-party lab and verified to be safe from over 300 harmful substances. Duvet Cover: Button closure; four interior corner ties keep it in place. Shams: Overlap closure. Made in a Fair Trade Certified™ facility, benefiting the workers who make it. Linen woven from European-grown flax, constructed in China.