A durable medical - grade, waterproof cover repels liquids and keeps allergens from entering the mattress core. (davincibaby.com)
When you get new prefolds, they will look HUGE and actually repel liquid if you use them without pre-washing them. (abbyslane.com)
When liquids, like tinkle, piddle, wee or whatever the heck you call it, smack into it, pointed and peaked geometric shapes in the paint repel the liquid. (entrepreneur.com)