Frequently Asked Questions about eVENT

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Is eVENT as durable as GoreTex Pac-Lite?

In order to answer this question, you have to understand that “eVENT” and “Pac-Lite” are membrane technologies, not fabric technologies. Consequently, either eVENT or Pac-Lite may be laminated to different face fabrics. Those face fabrics are most commonly, taslan or ripstop nylons, and vary widely in terms of weight. So, the durability of the overall fabric depends far more on the face fabric to which the membrane is laminated than on the technology itself. When used in gear and apparel where the inside of the fabric is exposed (e.g., raingear, tents, bivy sacks), eVENT fabrics have a tricot-faced inner lining (a typical “3-layer construction” that protects the eVENT membrane. In contrast, Pac-Lite fabrics have a very thin carbon coating to protect the Pac-Lite (Gore-Tex) membrane (what you might call a “2.5-layer construction”). Generally, it is assumed that tricot linings not only do a better job of dispersing moisture and promoting moisture vapor flux through the membrane, but they also tend to be more durable than 2 and 2.5 layer constructions.

Is eVENT a good fabric for a tent? Will it hold up in a wind storm?

eVENT is exceptional fabric for a tent or bivy sack. While condensation will form in a humid tent made of eVENT, much like it does on the inner wall of any tent, the tricot lining disperses moisture that promotes its transport (as vapor) through the eVENT membrane. In our testing of tents and bivies, we’ve found eVENT fabric shelters to be far more breathable than their Gore-Tex cousins of five years ago, and in most conditions, as or more breathable than their EPIC fabric counterparts. Because of the resilience of eVENT fabric (i.e., its resistance to deformation under tension, as a result of its 3-layer construction), it’s an excellent fabric in the wind. In direct comparisons of nearly identical shelters (Black Diamond Firstlight Tent, made with EPIC, and the Integral Designs eVENT MK1Lite), we found the MK1Lite to be more stormworthy in terms of both wind resistance (stability) and waterproofness. In addition, eVENT is a completely wind proof fabric.

For more information, please see Backpacking Light’s Single Wall Tent Reviews.

Is eVENT more breathable than GoreTex Paclite?

Yes. Breathability data for several waterproof breathable fabrics can be found in Waterproof Breathable Fabric Technologies: A Comprehensive Primer and State of the Market Technology Review at

How does a bivy made of eVENT compare to a bivy made of Epic?

In warm conditions, you won’t notice much difference – both are sufficiently breathable to pass normal moisture loads while sleeping, barring unusual circumstances. As temperatures drop (especially below the freezing point), you’ll find that both eVENT and EPIC bivies will exhibit condensation on their inner surfaces. However, the tricot lining of an eVENT fabric greatly helps to disperse liquid moisture across the inner side of the fabric, providing a greater surface area for evaporation that drives the moisture through the fabric. Consequently, it’s been our experience that bivy sacks made with eVENT fabric perform better in most conditions than bivy sacks made with EPIC fabrics. Here’s the kicker: as moisture passes through EPIC (because EPIC is permeable to liquid moisture), it blocks the pores that allow it to breathe. Thus, as EPIC gets wet (from dew, condensation, etc.), its breathability decreases dramatically, compounding the condensation problem. In addition, eVENT is completely waterproof, while EPIC is not. The only situations we’d recommend an EPIC bivy over an eVENT bivy is in warmer, drier conditions. EPIC bivies are ideally suited, for example, for summertime camping under a tarp, as they provide sufficient water resistance to protect your sleeping bag from rain spray.

How does a shelter made of eVENT compare to a shelter made of silnylon?

eVENT is breathable. Silnylon is not. Silnylon shelters, especially those that are completely enclosed, will suffer from significant condensation problems as the temperature drops.

How does a jacket made of eVENT compare to a jacket made of GoreTex PacLite?

Both are quite breathable, but eVENT will keep you more comfortable as the temperature drops to near freezing or lower, when Pac-Lite suffers from significant condensation on the inner membrane. eVENT jackets, because they are made with a three layer fabric, will be less compressible and slightly heavier than the lightest Pac-Lite jackets of the same design.

How does eVENT compare to the proprietary fabrics from Montbell, and GoLite (Alchemy)?

Most of these proprietary fabrics are two, 2.5, or three layer polyurethane coated fabrics, and as such, are not as breathable as eVENT. The exception is a Toray fabric known as Entrant DT, which has unique properties that allow it to breathe nearly as well as many of the high end waterproof-breathable fabrics, including Gore-Tex XCR and eVENT. However, this latter fabric has not been on the market long, and much field testing and experience still needs to be gleaned in order to made responsible judgments about its performance.

Dr. Ryan Jordan is the Publisher of Backpacking Light Magazine, home to a product review team consisting exclusively of scientists and engineers, many of whom hold degrees in engineering and science. One of Backpacking Light’s core values is the communication of responsible product review and analysis based on sound science and good field judgment. For more information please visit Backpacking Light Online.

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