DWR (Durable Water Repellent), What is it?
DWR (Durable Water Repellent) is a coating added to the fabric at the factory to make it waterproof (hydrophobic).
How does it serve me?
Know the following differences:
Water Resistant: as long as it is has the basic ability to keep some water from reaching your skin
DWR: increases the water resistance of any jacket. The DWR does this by adding It also prevents the surface of the waterproof/breathable jacket from accumulating so that the jacket can run at maximum efficiency.
Water-Proof: the item’s fabric has abilities from stopping water sipping through it. It sounds suffocating, but some fabrics are able to achieve waterproofing & breathable at the same time, such as Gore-Tex fabric.
What is the benefit?
source: Gear Junkie
It Keeps you dry! Moreover, it is common in terms of availability, and more sustainable as recently Chemical Vapor Deposition (CVD, a professional term for spraying at a minimum level), is being applied.
Additionally, it’s renewable too post-wear-off due to abrasion, oil stains due to frequent usage. Just wash the item (yes, wash it, with cold water) and do a heat drying. If the effect is still not being seen, then spray it with some DWR spray yourself. Such sprays are everywhere in the internet.
Note: Waterproof Items can also have DWR applied. Since it avoids water gathering on the fabric, keeping the jacket’s waterproof capability at the maximum.
What is the downside?
However, this coating cannot tackle heavy rain. Your need the fabric to have waterproof characteristics to handle that. Moreover, reapplication of the DWR does take some effort.
All in all, If you need extreme waterproof feature, go for waterproof-fabric-made items such as Gore-Tex items. Overall, this feature is still very useful for urban and rural transit or urban technical gears.