Polytetrafluoroethylene, (PTFE) can be used for Thin coatings, which is waterproof  and  applied without noticeably changing its weight.

Polytetrafluoroethylene, (PTFE) is a durable plastic substance that can be used to coat just about anything. Derived from research done at Massachusetts Institute of Technology with Professor Karen Gleason, GVD's coating system is based in a process called chemical vapor deposition (CVD), which uses a gas rather than a traditional liquid, evenly coating items without exposing them to solvents or extreme heat.GVD's coatings can also be as thin as five nanometers - a ten thousandth of a human hair. The coating is so sensitively applied that it can waterproof a napkin without noticeably changing its weight.

PTFE has the same chemical make-up as Teflon, and is most often associated with the non-stick surfaces of cookware. But this common coating can be used for more than keeping your egg yolk from breaking according to Hilton G. Pryce Lewis of GVD Corporation.