Waterproof and breathable fabrics

I have recently been looking into fabrics that are both waterproof and breathable for outdoor use.

These kinds of material are used by hikers, walkers, mountaineers and many who pursue outdoor hobbies. They have the advantage of keeping the water out, but allowing water vapour, in the form of sweat, to escape.

These fabrics are comparatively new and market leaders in the field include names like GoreTex and Event.

Clothing made from these waterproof and breathable fabrics can be quite expensive with a jacket generally starting at around £50 ($75) and ascending to the several hundreds of pounds or dollars.

How they work

The waterproof concept of this type of clothing is fairly easy to understand. The weatherproof material prevents water from getting in, however the breathable element relates to two separate functions, both of which stop the wearer feeling hot and sweaty.

Firstly, the pores in the fabric are too small for water droplets to pass through, but sufficiently big enough for water vapour to pass through.

Secondly, this type of clothing has an inner layer that quickly takes sweat from the body and passes it from the internal surface to the external surface of the material. This is often referred to as wicking and it is this feature of outdoor clothing that results in the high costs and superior performance.