Luv Bug Little Dreamer Waterproof Crib Sheet (Heart) in box Our crib sheets are a perfect backdrop matching your baby’s personality. They’re the best accessory to snap the perfect picture that will be treasured for years to come. The waterproof backing eliminates the need for a protective mattress cover leaving only the top sheet to change. Fits most mattress - 28 x 52 . Our crib sheets are a perfect backdrop matching your baby’s personality. They’re the best accessory to snap the perfect picture that will be treasured for years to come. The waterproof backing eliminates the need for a protective mattress cover leaving only the top sheet to change. Fits most mattress - 28 x 52 .