Full 400 Thread Count Performance Flat Sheet Metallic Blue - Threshold: Cotton The Full 400 Thread Count Performance Flat Sheet in Metallic Blue by Threshold is made of 100% cotton with a luxurious solid color design. This rectangular flat sheet is machine washable for easy care and features a thread count of 400, providing a comfortable and high-quality sleep experience. Ideal for adults in a bedroom setting, this flat sheet from Threshold offers a stylish and elegant addition to any bedding collection. W10-20301