Waterproof paper is good for outdoor, marine, field use and general wet environments. Often designed especially for printing topographic maps. It is normally durable and tear-resistant.
The paper is created with special coatings (plastic-coated paper) and fibers to allow it to stay together and not change shape or texture when exposed to rain, dampness, or immersed in water.
Waterproof paper is difficult to recycle.
References
Waterproof paper Wikipedia(Text) CC BY-SA