All in one: Waterproof Crib Sheet / Toddler Bed Sheet and Crib Mattress Pad Cover Our Waterproof crib sheet is lined throughout with Eco-friendly TPU especially designed with no seams to prevent leakage, so no mattress pad cover, mattress liner or crib mattress protector is necessary. Clean up is a breeze and your crib and toddler mattress are fully protected. Soft and Breathy: 100% Jersey Cotton Our Crib Sheet Sets are composed of light, soft and breathable fabric. Made from 100% high quality Jersey knit cotton, babies and toddlers love our Crib sheets, as they offer a soft, welcoming texture that lulls them into restful sleep.