Grown in California, American Supima cotton is known for its quality and elegance due to its extra long staple cotton fiber length. Long staple cotton increases the softness and silkiness of the sheet, while reducing pilling, and giving incredible luster to the woven sateen fabric. Backed by the Supima cotton certification board for trusted authenticity. This sheet set also includes the GripOn patented fitted sheet techonology, which is a fully elasticized band that hugs your mattress to prevent shifting. Color Raindrop.