Cotton PREMIUM COTTON PERCALE PILLOWCASE: Provides the optimal mix of comfort, durability and easy care. No added chemicals, flame retardants or formaldehyde. MIX & MATCH: Designed with toddlers in mind, let them mix & match fun prints and inspiring colors to personalize their dream space. Sheets, pillowcases, and pillows sold separately. EXTRA DURABLE & LONG-LASTING: 200 thread count makes these pillowcases extra durable to last through the toddler stage. Use with BreathableBaby Toddler Pillows (sold separately). Do not use before 2 years of age. EASY CARE & SOFTER WITH EVERY WASH: Machine wash, tumble dry low. Wrinkle and shrink-resistant 100% cotton gets softer with every wash. And the 2-pack means there's always a backup. FITS 13" x 18" TODDLER PILLOWS: Carefully crafted to fit toddler pillows measuring 13" x 18" (33 x 46 cm).