Abbreviation of the three words "Durable Water Repellent". This is a special surface treatment of the upper fabric, which makes it non-wetting for a long time. Be careful not to confuse with waterproofness.
The treatment maintains the surface tension of the top fabric. During the rain, droplets form on the surface, which do not sink in and flow down freely. Sometimes this treatment is mistaken for waterproofness.
Although DWR can partially and for a limited time withstand light rain or drizzle, for clothing to be truly waterproof, it must be made of membrane laminate and perfectly sealed.
For waterproof clothing, proper DWR function has an irreplaceable role and is very important for user comfort. If water, or at least a part of it, can run down the top fabric and does not soak into the top fabric, the clothes will not become heavier with water, the jacket will not get cold and can "breathe" better. As a result, we feel much more comfortable.
Clothes also dry much faster. If the DWR does not work, we may even get the impression that water is leaking through when in fact it is not.
For clothing without a membrane, windbreakers or softshell, a functional DWR will help prevent soaking and drying faster, at least for a limited time.
DWR is always applied to a new product directly from the manufacturer. Unfortunately, this treatment is not eternal, and its parameters are gradually reduced by use, washing, dirt and grease.
So, once we find out that the top fabric becomes absorbent, it’s time to renew it. If we are going to a longer hike, we also recommend renewing the DWR.
Currently, manufacturers are trying to make DWR less harmful to the environment. The composition is therefore different than it was years ago. The new ecological treatments also work well, but they do not last for as long as in the past and it is therefore necessary to impregnate more often.
Fortunately, the re-application is simple and can be done with impregnation sprays. We do not recommend bath-based impregnation, it is better to impregnate after washing and apply it only on the top fabric.
Follow the instructions for the product, however the procedure is basically the same for all clothing: