Water repellent is a wet, usually semi-durable finish applied to yarn rather than a finished fabric in order to resist the penetration of water while allowing the passage of air and moisture. The finish can be a wax emulsion or other chemical, and each option varies in efficacy, toxicity and eco-friendliness.
Fabrics that have been treated with a finish which cause them to shed water and resist water penetration, but are still air-permeable. Treatments can include wax coatings, resins, silicones, and fluorine derivatives. Such treatments do not close the pours of the fabric, while waterproof finishes do.
Fabrics that have been treated to resist wetting and shed water by causing the water to bead on the surface. It does not close the pores of the fabric as waterproof treatments do, so the fabrics are comfortable to wear. It will offer protection in a light shower but not heavy rain. Water repellency may be added by treating the fabric with fluorocarbon chemicals, wax, silicone or resins. Sometimes called water resistant.
A type of finish applied to a textile fabric and that prevents the spreading of globules of water over its surface.
The term is normally not applied to a water-repellent finish that is impervious to air; this is generally referred to as "waterproof".
A term applied to fabrics that have been treated with a finish which causes them to shed water, but are still air-permeable.