It takes more than a high thread count to create truly superior sheets. Case in point: our sumptuous 400-count Supima sateen bedding. Supima is a rare American cotton — just 3% of the U.s. crop qualifies. It takes this bedding from silky to positively indulgent — and makes sleep serene. Our gentle No Iron finish lets you take it from the dryer to the bed without a wrinkle. Duvet Cover has internal corner ties to prevent shifting.Supima is conscientiously sourced, American-grown cotton that s farmed to minimize environmental impact.