According to the European standard EN343, for materials and products to be considered waterproof they need to meet specific criteria.
This criteria includes the amount of water pressure (psi) they can withstand before leaking or an “mm/24 hours” rating which equals the
amount of rainfall a fabric can withstand in a single day before water starts to leak through.
Equally important are the abrasion resistance quality of the membrane, the coating and waterproof quality of the seams and
zips – these should be laminated or welded.
The water-and wind-resistant soft shell material provides good protection from the dangerous wind chill effect, which results from air
getting through the material to the skin. Coated soft shells without membranes usually offer higher breathability but are less water-repellent.
However, when being exposed to rain for several hours, one should in any case have a waterproof rain jacket in reserve. It is recommendable to
fall back on a waterproof jacket during persistent rain. The seams of wind-resistant functional textiles are not welded or laminated,
which distinguishes wind-resistant from windproof.
Breathability refers to the ability of a man-made fibre or natural fibre to release the body's own water vapor.
Breathable fabrics allow for quick drying already during use and thus prevent both heat build-up from the body under the fabric
as well as cooling due to dammed up moisture.