Waterproof & Breathable Outerwear

Good outerwear is very important in mountain activity. 
And one of the best for this is waterproof/breathable jacket.
Someone that going to the mountain will be better if he/she carry this outerwear.

Waterproof/breathable fabrics are defined as fabrics that will withstand over 1000 millimetres of water (9.8 kPa) pressure without leaking (see hydrostatic head), whilst allowing water vapour to pass through. Their most common use is in outdoor sports clothing and single wall tents, because of their ability to allow sweat to evaporate while remaining impervious to rain.

Rain room tests show that certain fabrics with less than 1000 millimetres hydrostatic head can keep you dry. Such garments tested in the Leeds University Rain Room show no signs of leakage after 4 hours of heavy simulated rain, 5 times heavy British rain. However, some garments made from fabrics that exceed 20 000mm have leaked due to the design of zips, hoods etc. Pressure may not be a good measure for rain wear, as the force of the rain drop on the fabric depends on how much the fabric moves. However, pressure is a good measure for sitting on wet ground or similar situations.

Fabric construction which directs water away from the body can be used to keep the wearer dry, rather than membranes, coatings or laminates. This means that perspiration can be moved away from the body too more effectively as both liquid water and water vapour can be directed. These are generally called Directional Waterproof fabrics rather than breathable.

The breathability of all waterproof/breathable fabrics is very dependant on conditions. When the fabrics become chilled or humidity is high, the dew point may be reached and condensation will occur.

Some common waterproof/breathable fabrics are:
Nikwax Directional Textiles as used by Páramo Directional Clothing Systems
Feather and Fur Technology supplied by FurTech
Gore-Tex
eVENT
Sympatex
3-ply Entrant-EV™membrane Mountain Equipment Co-op
Drilite Extreme, made by Mountain Equipment
HyVent, made by The North Face
H2No, made by Patagonia, Inc|Patagonia
Omni-Tech by Columbia
Conduit, made by Mountain Hardwear
Triplepoint Ceramic, made by Lowe Alpine
Precip, made by Marmot
Watergate, made by Outdoor Designs
Closely woven cotton
Polymer-encapsulated cotten EPIC, made by Nextec
Wax impregnated cotton or cotton/polyester mixes (such as those used in Barbour coats and Fjällräven's G-1000 fabric)
Epoxy (any maker,do not advertise in Wikipedia)
Hyper-Dri by Mark's work wearhouse
Ventile by Ventile