X-tex fabric has a woven textile face with a coating to make it both waterproof and breathable.
This is a 50 denier polyester. 50 denier is a heavyweight yarn by today’s standards, but important for a mountaineering tent as the intrinsic strength of a fabric is derived primarily from the thickness of the yarn. We have chosen polyester over nylon as it has superior resistance to UV-degradation.
The higher the altitude, the more UV there is, and as bivouac tents are usually found up high, the resistance to UV becomes important in product longevity.
The coating substrate is polyurethane (PU). This has a monolithic structure (ie non-porous) which gives it an outstanding water-column for water resistance (20,000+ mm, or 30+ psi). The coating ‘breathes’ by transporting the water molecules through hydrophilic attraction, a mechanism used by a large number of branded fabrics used in waterproof/breathable garments.
However, a PU coating on its own is insufficient to deal with the condensation experienced in single-wall tents as the moisture build-up overloads the fabric’s ability to absorb it. To manage this, the polyurethane coating is impregnated with activated-carbon. This greatly increases the surface area available for the absorption of the water molecules to the degree that these stay in the dis-associated state (ie., they don’t form droplets), continue to diffuse through the coating (ie., the fabric breathes) and the fabric itself remains dry to the touch.