Waterproof bedding protection is best with a Beautyrest Cotton Top Mattress Pads. This works to protect leaks and spills of any type of liquid, leaving no stains onto the mattress.

The pad is made of four ply 100$ cotton on a 200 thread count surface with 4oz. polyester fiberfill.

The Beautyrest pad has vinyl waterproofing, with breathable protection.  It can supposedly hold six cups of fluid.

• Super-absorbent, four layers of waterproof mattress protection for extra padding and comfort
• 100% cotton top with soft 200 thread count – fits mattresses up to 20″ deep
• 100% Waterproof yet Breathable: Polyurethane laminated barrier protects your mattress from leaks while providing breathable comfort
• No vinyl to crinkle or trap body heat while you sleep!
• Machine wash warm / tumble dry

Via Beautyrest at Amazon