Waterproof fabric, or impermeable in French, refers to a water-resistant material. This technical specificity can be revealed on three levels: either the material is naturally waterproof thanks to the fibers that compose it, or it is treated with a waterproof coating to become a water-repellent fabric; or finally, the density of its weaving is very high, which gives it particular water resistance.
The subtlety between a waterproof material and a water-repellent fabric? Their resistance over time. The waterproof fabric will be the most robust: often made from rubber or plastic, its waterproofness is total, unlike water-repellent fabric. Generally made of cotton or polyester, a material becomes water-repellent after a durable water-repellent (DWR) treatment applied to its exterior surface. Thanks to this finish, water runs off the fabric, without impregnating it. However, the hydrophobic powers of water-repellent fabric are not permanent; it is therefore sometimes necessary to reactivate them with a new treatment.
In any case, whether waterproof or water-repellent, waterproof fabric is attractive today with its different aspects (coated cotton, oilcloth, ripstop nylon, polyester outdoor fabric, etc.) and is used in many areas. Including that of fashion!