A pillow sham is a decorative pillow case that can transform any normal-sized pillow into a stylish accessory for your bedding set. Pillow shams come in three traditional sizes: Standard Sham (26″ x 20″), King Sham (36″ x 20″), and Euro Sham (26″ x 26″). Unlike typical pillowcases, most pillow shams are open in the middle of the back with slightly overlapped fabric. However, some do have zippers to close them shut. You can usually find pillows sold in pairs made out of coordinating fabrics to match your duvet cover.