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