Water density and breathability


When clothing claims to be waterproof, not the whole truth is told. That’s why we at Ocean Rainwear choose to expand on the information.

Our products are made of either polyester/cotton/PVC, polyester/PU or a 3-layer fabric with membrane between them. The three different fabrics have different qualities, depending on use.

No textile is 100% waterproof. Water will penetrate the fabric as the water pressure increases. This is true for all textiles. In practice a product that is able to resist a water column of 15.000-20.000 mm feels waterproof, as we only exceed this column in extreme situations.

Cotton/polyester/PVC, which we use, resists a water column of 15.000-20.000 mm.

Because polyester/PU is a little thinner and stretchable it feels more comfortable to wear. We use a fabric resisting water column of 8.000 mm. When using this fabric it is possible for water to penetrate if you sit on a wet bike saddle or a wet seat of a tractor. This also applies if sailing in rough seas.

This is also relevant for 3-layer products with membrane like, for instance, Tritex or polyester coated with PU-membrane.

The dilemma for the customer is deciding, on the one hand, how much water column a product should be able to resist and, on the other, the comfort and the breathability. Therefore, when choosing a product, it is crucial to consider for which purpose the product is needed.

Breathability is measured in mvp = moisture vapour perspiration. MVP tells you how much moisture can vaporise through the fabric per m2 per 24 hours. The higher the number, the higher the wear comfort.