What is the name of Carhartt's proprietary water-repellent finish?

Carhartt’s proprietary water-repellent finish is called Rain Defender.

Rain Defender is Carhartt’s name for a durable water-repellent, or DWR, treatment used on selected garments. The finish helps light rain and water bead up and roll off the surface instead of immediately soaking into the fabric. It appears on products including jackets, sweatshirts, shirts, and other outerwear.

The treatment is intended for light rain and wet conditions, not as a synonym for a fully waterproof shell. That distinction matters: a DWR finish can improve surface water resistance while still allowing a garment to feel more flexible and breathable than heavy rain gear. Repeated wear, abrasion, washing, and exposure to dirt can gradually reduce the effect.

Rain Defender is also easy to confuse with Storm Defender. Storm Defender is Carhartt’s waterproof-breathable rainwear technology, while Rain Defender is the durable water-repellent finish used to help shed lighter precipitation. Rugged Flex, meanwhile, is the brand’s stretch technology and has nothing specifically to do with water resistance.

The name “Rain Defender” therefore identifies the finish and product technology, not a separate fabric fiber or a claim that every garment carrying it is completely waterproof.