The Serta Perfect Sleeper 310 Thread Count Cotton Rich Sheet Set is an ideal pairing for your new comforter or duvet. Featuring a 310 thread count, these flat sheets are soft and durable, made from a blend of 65% cotton/35% polyester. Blue, khaki, ivory, and white colors are available, each with matching pillowcases. Sheets are oversized to help fit most any standard-sized mattresses up to 19-inches deep. Machine washable. Twin, full, queen, and king sizes are available (see below for dimensions).