Here is something different. 

A 100% cotton top, waterproof fitted sheet.  Pop it over your mattress and sleep directly on top so it works as a fitted sheet and mattress protector in one.

Breathable – yet waterproof.

Composition
Top: 100% cotton
Backing: 100% polyester backed polyurethane

Care instructions:
Cold or warm gentle wash.  Tumble dry on low.  Do not bleach or dry clean.