All in one: Quilted Waterproof Pack n Play/Portable Crib Sheet and Pack n Play Mattress Pad Cover Our Quilted Waterproof Pack n Play sheet is lined throughout with Heated Protected TPU especially designed to prevent leakage, so no mattress pad cover, mattress liner or mattress protector for your pack n play and mini crib is necessary. Clean up is a breeze and your portable crib and pack & play mattress and mat are fully protected. Soft and Breathy: 100% Jersey Cotton Our Pack n Play/Portable Crib Sheet Sets are composed of light, soft and breathable fabric. Made from 100% high quality Jersey knit cotton. Babies love our Pack n Play sheets, as they offer a soft, cozy quilted texture that lulls them into restful sleep.