This well-known material, long used in conservation to slowly humidify parchment is now available again, only at CXD!
The new Humidification membrane from Porelle is made of expanded PTFE laminated to a 100% non-woven polyester.
The "Hydra Air PTFE" membrane has unique oleophobic properties, an outstanding wash resistance and is completely inert.
The pore size is approx. 0.2 micron creating a controlled water vapour permeability just like the original Gore-tex but with an exceptionally high air flow of 0.4 CFM (Ft3/min.)
Because of the small pore size, water and many organic solvents penetrate this membrane as vapour rather than as a liquid.