Breathable outdoor wear keeps you cool and comfortable during hot weather by allowing body heat to escape and perspiration to dissipate through. In colder climates, such fabrics also help you maintain an acceptable core temperature.

When it comes to waterproof-breathable apparel, an ideal jacket would be one that provides complete waterproof protection in rainy conditions while remaining highly breathable when hiking or climbing. But how can this be accomplished?

Waterproof Breathable Fabrics

Waterproof, breathable fabrics offer protection from wind and rain while still allowing perspiration to escape, thus preserving body heat loss. These versatile pieces of clothing can be tailored to suit various activities and pair best with moisture-wicking base layers and thermal mid layers for optimum performance.

Waterproof fabrics are created by coating them or laminating them to prevent liquid water from penetrating their fabric surface. PVC- or polyurethane-coated fabric garments such as jackets and rain pants are common examples, with DWR finishes further increasing waterproof properties.

Fabrics that resist water column or vapor transfer ratings are often graded according to their resistance, though testing methods don’t adhere to any uniform standardization process. Lameted waterproof fabrics like Gore-Tex often feature highly breathable membranes like ePTFE or PU combined with polyester or nylon face fabrics treated with DWR to protect from elements.

Waterproof Breathable Membranes

Membrane-based fabrics like Gore-Tex and eVent have long been considered the gold standard in waterproof breathable jackets, and continue to push the limits of breathability. But other membrane types, including polyurethane (PU) and polyester membranes (PET), are quickly catching up and offering hikers and climbers unprecedented performance levels.

Waterproof breathable membranes feature pores that are too small for liquid water to pass through but large enough for sweat vapor molecules to flow freely through. To further ensure breathability, these pores are sealed off with durable water repellent (DWR) treatment that repels rain and snow from seeping in and an oleophobic treatment that keeps out oil, dirt and other contaminants that might compromise it.

Keep in mind that membrane jackets tend to be heavier, less packable and more costly than coating jackets; so when choosing one it is essential to consider both your needs and budget before selecting fabric. Many ski tourers opt for membrane jackets which only waterproof on arms and shoulders but provide breathability elsewhere – this could be beneficial when touring on snow.

Waterproof Breathable Face Fabrics

Waterproof and breathable jackets, parkas, rain pants, gloves and hats are essential accessories for outdoor enthusiasts. In order to be truly breathable, any piece of outerwear must simultaneously keep moisture (such as perspiration) at bay while allowing excess body heat to escape – and for this to occur effectively requires both a waterproof membrane and exterior face fabric in its construction.

Most waterproof breathable fabrics use hydrophobic membranes with crystalline structures that repel droplets of moisture rather than absorb them, leading to beading and rolling off as opposed to being absorbed by the membrane. They then typically feature DWR treatments that prevent it from becoming saturated by precipitation.

2-layer and 2.5-layer fabrics typically feature a face fabric bonded directly to a waterproof breathable membrane, with an interior mesh protective liner hanging loose inside. However, some 2-L garments include Gore-Tex Paclite Plus fabric which eliminates this need by screening raised patterns onto its interior for increased abrasion resistance, breathability, and weight savings.

Waterproof Breathable Back Fabrics

Waterproof breathable fabrics provide protection from precipitation while permitting perspiration vapors to escape, keeping you dry and comfortable in outdoor clothing and equipment like tents, outerwear, backpacks and sports gear.

Most outdoor fabrics are treated at the factory with a Durable Water Repellent (DWR), increasing surface tension of fabric so water bead up and roll off instead of seeping into inner layers and leaving you wet. Unfortunately, due to falls and wear-and-tear from pack straps or chairlift rides, this DWR may wear off over time; thus making regular washing and treating essential to maintaining waterproof performance.

GORE-TEX, eVent and the new generation of thin polyurethane membranes such as Polartec Neoshell, Pertex Shield+ and Mountain Hardwear Dry.Q Elite are all extremely waterproof and breathable materials; two have face fabrics which must be lined for added permeability while others may cover their membrane with protective fabric for enhanced protection and do not need lining.