Rainwear is one of the most popular subjects among lightweight backpackers. That’s easy to understand, because we are dependent on our rainwear to keep us dry and warm when the weather turns wet. Plus, rainwear has multiple uses; it also serves as windwear and as an outer shell layer in camp. We are always looking for the most performance and dependability for the least amount of weight.
The author wearing The North Face Triumph Anorak (5.4 ounces, size M) and Tyvek pants (2.2 ounces, size L) at 12,300 feet in the Weminuche Wilderness, Colorado. Lightweight rainwear also serves as windwear and an outer shell layer in camp, as shown here. It rained for four hours just after this photo was taken.
I am writing this rainwear update as part of Backpacking Light’s summer 2008 Outdoor Retailer coverage. My purposes are to summarize Backpacking Light’s current favorite lightweight rainwear in several categories and to highlight emerging new technologies and product introductions we found at the summer 2008 Outdoor Retailer trade show. This update is not meant to be comprehensive, like our Rainwear State of the Market Reports, the last of which was our 2005 Lightweight Rainwear Review Summary and Gear Guide Overview by Don Wilson. Rather, it will concentrate only on rainwear that we consider to be the lightweight standouts for backpacking. In doing so, I will incorporate some favorites and tips from the Backpacking Light staff on rainwear selection and use.
The categories I will be covering are eVENT, Gore-Tex, polyurethane laminates, Propore, Tyvek, and silnylon. Each (except silnylon) is a different waterproof/breathable technology. For a thorough description of these technologies, I recommend reading Waterproof Breathable Fabric Technologies: A Comprehensive Primer and State of the Market Technology Review by Alan Dixon and The Science of Breathability and Its Impact on Raingear Selection and Use by Ryan Jordan and Stuart Bilby. These articles by our Backpacking Light founding gurus provide a solid foundation for understanding waterproof-breathable technologies and garment physics as a basis for selecting rainwear.
Our arbitrary weight limit is eight ounces for a waterproof/breathable rain jacket with a hood. That reduces the field a lot, which is our purpose in this article. In order to include eVENT and Gore-Tex Pro Shell jackets in our selections, we had to raise the limit a bit. All weights are for a size medium, unless stated otherwise.
Although all of the rainwear discussed in this article is "waterproof-breathable," there are definite limits to their breathability. Here are a few rainwear facts to keep in mind:
- While many WP/B garments will be comfortable at lower activity levels and cool/overcast/breezy conditions, all of them will be a sauna inside if you wear them while hiking uphill carrying a pack in warmer temperatures.
- PTFE laminates (like eVENT and Gore-Tex) breathe better than most other technologies, which means garments have a wider comfort range before they get steamy inside.
- Ventilation is more important than fabric breathability. Opening pit zips, core vents, and a full front zipper make a huge difference in maintaining comfort.
- Carrying a backpack interferes with fabric breathability and garment ventilation a lot.
- We perspire a lot more from our torso area than from our legs. Therefore, we can be comfortable with less breathable (and cheaper) rain pants.
- PTFE laminates (Gore-Tex and eVENT) require maintenance (cleaning and restoration of the surface DWR) to keep them waterproof.
- When only showers are expected, a highly water-resistant windshirt is much more breathable than any WP/B rainwear that has a membrane.
The bottom line is that "highly breathable" rainwear is not a silver bullet. Any highly breathable jacket with minimal ventilation options will easily be overwhelmed by perspiration at higher exertion levels. Ventilation is critical to making a jacket comfortable, especially when hiking uphill carrying a backpack. Carrying a backpack on top of a rain jacket interferes with breathability and ventilation because it covers your backside, the hipbelt seals the bottom, and the sternum strap reduces the effectiveness of opening the front zipper (I usually don’t use the sternum strap when I’m wearing a rain jacket so I can get more ventilation when I need it). The situation is exacerbated by the fact that rainwear manufacturers rely on fabric breathability too much and remove ventilation options like pit zips and core vents to save weight and money. Ideally, what we really need is rainwear made of highly breathable fabric, plus several effective ventilation options that work with a backpack, with minimal weight.
eVENT fabric (an ePTFE laminate) is the gold standard for breathability and (along with Gore-Tex rainwear) is the most expensive. Unfortunately, not much has changed in this category. Most eVENT fabric in current jackets is a three-layer construction with a nylon face around 30 denier, resulting in a heavier, stiffer garment. Consequently, the weight of the lightest eVENT jackets is still in the ten- to thirteen-ounce range.
This begs the question: Why has the weight of eVENT jackets stalled? We have Gore-Tex PacLite jackets in the six- to eight-ounce range (see below), so why not an eVENT jacket in the same range? Many of the PacLite jackets (see below) have a 15 denier face fabric and an essential feature set and come in under eight ounces, so why is eVENT lagging behind? In Europe, Crux and CAMP are now using a two-layer eVENT sleeping bag shell that is very soft and light – it has to be for a sleeping bag shell. So, we know they can do it, but why don’t we have lighter eVENT constructions for rainwear? Is the demand not there?
To find answers to these questions, I visited the eVENT booth at Outdoor Retailer and got the following response from eVENT representative Anna McCormack (paraphrased): "Manufacturers are already using face fabrics down to 20 denier (in Japan), and eVENT’s new factory in Shanghai is open to laminating the ePTFE membrane to nearly any fabric, so lighter eVENT fabrics are readily available and can go lighter. The need is for manufacturers to take the initiative to construct a lighter eVENT jacket; it’s in their ball park. They need to select lighter fabric constructions, garment designs, and features to pare the weight down. A sub-eight-ounce eVENT jacket is easily attainable, if manufacturers want to do it."
So apparel manufacturers, we’re issuing the sub-eight-ounce eVENT jacket challenge: give us a really light eVENT jacket with an essential feature set, and we will pounce on it! We want to see some movement in the development of lighter eVENT fabrics and garments.
Speaking of improved eVENT technology, the word on the street is that the new lamination factory General Electric built for eVENT fabric production frees eVENT from a third party producer (and its preference to use in-house face fabrics) and opens the door to the use of a wide array of face fabrics with eVENT. So, look for a greater variety of fabric constructions in the future. Also, eVENT has an improved process to apply their proprietary oligophobic coating on the ePTFE membrane that will result in increased breathability of garments produced after summer 2009. We don’t have any information on the actual percentage increase at this time.
The current lightest and still our favorite is the Integral Designs eVENT Rain Jacket (8.9 ounces, US$240). Mike Martin notes: "My favorite for bushwhacking, skiing, and guaranteed sloppy conditions; 10.2 ounces in XL." It’s my favorite too, because of its light weight and simplicity. The non-adjustable unbrimmed hood has an elastic hem that fits just fine. Hikers who don’t like the shorter body length can opt for the Integral Designs eVENT Thru Hiker Jacket (11.9 ounces, US$260) which is three inches longer.
A close contender that we found at summer OR is the CAMP A-Event Anorak (9.6 ounces), which is now available throughout Europe, but won’t be available in the U.S. until 2010, when CAMP plans to introduce more of their products. The anorak has an angled zipper to the left side of the hood to prevent chin chafing, a kangaroo front pocket, a sleeve pocket, and drawcord adjustors on the hood, cuffs, and hem. A full-zip jacket and pant will also be available.
CAMP’s A-Event anorak (9.6 ounces) is the second lightest eVENT jacket around and features a unique angled zipper to the left side of the hood to eliminate chin chafing. The companion pant weighs 10.5 ounces, which is similar to pants from Integral Designs and Rab. CAMP apparel is available throughout Europe, but won’t be available in the U.S. until 2010.
A new addition to the Rab line of eVENT clothing is the Momentum Jacket (12 ounces, US$285), made of soft three-layer eVENT and featuring two zippered chest pockets and a wire brimmed helmet-compatible hood. The popular Drillium (13 ounces, US$275) will be updated for spring 2009 with a softer/lighter eVENT fabric, some changes to the roll-away hood, and the addition of an internal pocket, all of which increase the weight by one ounce. They also added a women’s version of the Drillium jacket and unisex Drillium pants (10 ounces, US$175).
Doug Johnson’s favorite jacket is the Montane Quick Fire (11 ounces, about US$348) which has a stow-away hood and seems to be very similar to the Rab Drillium. Some really good news is that Montane gear is coming to the U.S. in spring 2009 through an exclusive dealership with Backcountry.com. Montane has a wide range of really light apparel of interest for lightweight backpacking, so we welcome their arrival with open arms.
The Integral Designs eVENT Rain Jacket (left) is the lightest available (8.9 ounces) and our favorite. The new Rab Momentum Jacket (center) is not the lightest but has a nice feature set for its twelve-ounce weight. The Montane Atomic DT Jacket (right) is made of Entrant DT fabric, which is more breathable than Gore-Tex.
Another significant event (so to speak) is that eVENT is coming to an REI store near you.
The new REI eVENT Shuksan Jacket for men (left, 17.8 ounces, US$289) and Kulshan Jacket for women (right) have lots of exterior and interior pockets, which accounts for their higher weight. These jackets and pants (not shown) are probably most suitable for mountaineering and backcountry skiing.
REI and eVENT have announced a new partnership to launch a technical, high-end, REI-branded outerwear collection made with eVENT fabrics. The first products to be introduced in fall 2008 are the Shuksan and Kulshan jacket and pants. The feature-rich jacket in men’s large isn’t the lightest (17.8 ounces), but it is full featured and really nice. The companion pant weighs a whopping 22.7 ounces and (in my opinion) is only really useful as a ski pant. Planned MSRPs are US$289 for the jacket and US$229 for the pant.
The Montane Atomic DT Jacket (8 oz, US$179) is made of a fabric called Entrant DT, which, according to Toray America, is a hydrophobic microporous membrane with a 15 denier nylon face fabric. The Atomic DT is one of Chris Townsend’s favorites. Chris notes: "I like the Atomic DT because it is a lightweight rain jacket suitable for severe conditions, as it has a big hood with a wired brim that gives full protection, and it has a double flap over the front zip. Ventilation is good too, as the cuffs are wide for good airflow in the sleeves and the big chest pockets are mesh-lined and so act as vents when open". According to Alan Dixon’s article on waterproof-breathable fabric technologies (referenced above), test data show that Entrant is more breathable than Gore-Tex, but not quite as breathable as eVENT. Its flat line of breathability versus relative humidity is similar to that of eVENT. Entrant fabrics are more common in Europe (especially the UK) but nearly unknown in the U.S. It has the potential to bring eVENT-like performance into lighter, less expensive garments – if it can penetrate the U.S. market dominated by Gore-Tex.
A maverick in this category is Montbell’s Breeze Dry-Tec technology. Montbell headquarters won’t let out what it is exactly, but it is claimed to be air permeable, so we suspect it is one of the Entrant technologies. Users have consistently praised its breathability. Montbell’s lightest jacket with this technology is the new for spring 2009 Outpace Parka (9.4 ounces, US$249), which sports a basic feature set and core-vent hand pockets for extra ventilation.
Montbell’s new Outpace Parka for spring 2009 (9.4 ounces) is made of the mysterious Breeze Dry-Tec fabric that is claimed to be air-permeable. Users have confirmed that Breeze Dry-Tec is very breathable.
Gore-Tex (an ePTFE-PU laminate) is the self-appointed Holy Grail of WP/B rainwear; their marketing machine has convinced many people that Gore-Tex is the "best" technology available with their "Guaranteed to keep you dry" tagline. Granted, it’s waterproof and durable, but it’s not as breathable as eVENT. The cost is about the same as eVENT rainwear.
As you probably know, standard Gore-Tex and Gore-Tex XCR have been replaced by Gore-Tex Pro Shell and Performance Shell, and Gore-Tex PacLite continues as the lightweight, more packable version. Pro Shell is more durable and breathable than PacLite, but most Pro Shell jackets are on the heavy side. However, the Montbell Thunderhead is an exception (12.1 ounces, US$298). It reduces weight and cost by incorporating panels of PacLite on the shoulders, has an essential feature set, and performs well because its large pit zips provide good supplemental ventilation. The Arc’Teryx Alpha LT (11 ounces, US$499) is entirely made of Pro Shell and aces the Montbell Thunderhead on weight, but it is very expensive.
Montbell’s Thunderhead Jacket (left, 12.1 ounces) is one of the lightest Gore-Tex Pro Shell jackets available. It has PacLite shoulder panels to save weight, and costs "only" US$298. The Arc’Teryx Alpha LT (right, 11 ounces) is lighter and elegantly made, but it costs US$499.
The really lightweight Gore-Tex jackets use PacLite for the entire garment. The lightest is Haglofs OZ Pullover (6.2 ounces) which uses a 15 denier nylon face fabric. Unfortunately, Haglofs does not have any U.S. dealers, but it is available in several European countries. In the U.S., the Outdoor Research Zealot (7.2 ounces, US$199) is the lightest PacLite Jacket, which also has a 15 denier face fabric and a full front zipper. Sorry, no pit zips on either jacket. Alan Dixon comments: "My favorite for cooler trips (e.g., the wet fjord-land coast of New Zealand’s South Island) in minimalist style is the Zealot."
The Haglofs OZ Pullover (left, 6.2 ounces) is the lightest Gore-Tex PacLite jacket, but it’s not available in the U.S. The Outdoor Research Zealot (right, 7.2 ounces) is the lightest one available in the U.S..
The well-designed new Marmot Nano Jacket (left, 8 ounces, US$250), available in spring 2009, will add another choice to the Gore-Tex PacLite category. On the right, the Salomon Minim Jacket barely misses our weight limit in the men’s version (8.4 ounces), but gets under our limit with the women’s version (7.4 ounces). With a little weight reduction, the Minim could be a low weight contender in the PacLite category.
Nearly every manufacturer has its own proprietary polyurethane laminate based waterproof/breathable rainwear. These constructions (a hydrophilic monolithic polyurethane laminate or coating on a face fabric) are less expensive to produce, garments are softer and more stuffable than ePTFE laminates, and they don’t require any particular maintenance. Another advantage of PU laminates (and PTFE laminates) is durability; even the thinnest constructions are adequately durable for backpacking.
Manufacturers are pushing the limits of lightness with very thin face fabrics and PU coatings, which also increases their breathability to some extent. Even so, the breathability of polyurethane laminates is limited by the technology itself – water must pass through the polyurethane layer by solid state diffusion, then evaporate from the outside surface, which is a slow process. The key to comfort with these jackets (or any rain jacket) is ventilation. However, many manufacturers cut ventilation features (like pit zips) to save weight, which is a clear tradeoff. The very lightest jacket may not be the most comfortable. The challenge is to retain ventilation options AND reduce weight, so theoretically there is a happy medium.
Unfortunately, we have lost some of the lighter rainwear in this category; the Patagonia Specter Pullover (6.5 ounces, US$225) is discontinued, the Montane 180 Pullover (7.1 ounces size L, US$167) is gone, and the current Sierra Designs Isotope (5.4 ounces in size L, US$90) will get a makeover and gain some weight in spring 2009 (more on that below). Things are constantly changing, and good gear comes and goes. Ryan Jordan’s comment: "My favorite is the Patagonia Specter. Old habits die young. I’m on my last one!"
The title of the lightest truly waterproof nylon-faced rain jacket goes to The North Face Triumph Anorak (5.4 ounces, US$179). Its thin, 15 denier HyVent DT fabric has an excellent DWR, holds up to prolonged rain, and is adequately durable. To achieve that weight, it’s mostly Spartan, but it does have a drawcord adjustable hood and hem and has one small chest pocket. The North Face Diad Jacket (7.8 ounces, US$199) is made of the same 15 denier HyVent DT fabric and kicks it up a notch. To achieve these low weights while retaining features, North Face has made an extraordinary effort to reduce weight by using thinner elastic drawcords, fewer adjustors, fewer seams, and narrow seam tape. Don Wilson really likes the Diad "because it has a great feature set for such a light jacket – full zip, eight-inch pit zips, chest pocket, two hand pockets, good cuffs, and nice hood with a lot of flexibility." Alan Dixon adds: "I prefer the Diad for warmer trips where I want the pockets, ventilation, and features. The Diad is a more flexible jacket adaptable to many conditions and needs, with a ton of features for the weight. It has a full zip (I’m not a big fan of pullover rain jackets like the Specter, although they are certainly appealing to some."
The North Face Triumph Anorak (left, 5.4 ounces) is the lightest nylon-faced rain jacket and is our favorite. The North Face Diad Jacket (right, 7.8 ounces) is our favorite full-featured rain jacket and is the only one in our lightweight roundup with pit zips. Both jackets are available in white, which would be a good choice for comfort in warmer conditions.
The Sierra Designs Isotope (5.4 ounces size L, US$90) ties The North Face Triumph on weight and exceeds it on features, but trails it on performance. The current Isotope will handle light showers okay, but wets through in prolonged rain. The Isotope Pant is different, as it’s made of a slightly heavier fabric than the jacket and its 5.6-ounce weight includes a zippered fly (men’s model), elastic waist drawcord, zippered rear pocket, and fourteen-inch ankle zips with Velcro closures. They have more features for the weight and cost US$70 (the same as the GoLite Reed pant), so the current Isotope Pant is a good value.
Sierra Design’s Isotope Jacket will receive a makeover for spring 2009. The new jacket will incorporate an improved Nanolite fabric with better breathability and Sierra Design’s Condor construction, a new pattern that increases freedom of movement. The downside is the weight will increase to eight ounces. Bummer on the weight increase, but the bright side may be better storm worthiness. We tried on the new Isotope at Outdoor Retailer, and found the men’s version to have a trimmer fit and the women’s model to have a looser fit. Overall, both jackets fit better than the previous version. The internal drop pockets are gone.
Sierra Design’s current Isotope jacket (left) weighs just 5.4 ounces (size L) and is full-featured, but it wets through in prolonged rain. It will receive a makeover for spring 2009 (right) with a new more breathable Nanolite fabric and new fit; the weight will increase to eight ounces.
The Marmot Essence jacket (8 ounces, US$150) is another lightweight contender in this field. It will get Marmot’s MemBrain Strata WP/B membrane technology (see below) for spring 2009.
The Mountain Hardwear Quark jacket (available now, 9.2 ounces in size L, US$200) is above our weight limit, but it has a significant redeeming factor – pit zips. This is the lightest rain jacket we know of that has full-length pit zips, fourteen inches long with double sliders (the pit zips on the North Face Diad are only eight inches long). Its 1.7 oz/yd2 Incite fabric, consisting of a Conduit membrane laminated to a printed brushed tricot, is a step forward in lightweight fabric technology. It’s like a really light mosquito netting with a thin waterproof-breathable membrane attached to it. The resulting fabric is very light and breathable, and Mountain Hardwear’s Z-Weld stitchless construction reduces garment weight. My only complaint is the heavier elastic cord used in the hood and hem drawcords; simply going to thinner elastic cords with fewer/lighter adjustors would get this jacket down near our eight ounce limit, which would be an excellent balance of light weight, breathability, ventilation options, and features. With a little weight reduction, it could easily challenge The North Face Diad jacket and the new Marmot Mica Jacket (see below).
In contrast, the spring 2009 Marmot Mica (men’s) and Crystalline (women’s) Jacket (6.5 ounces, US$130) seem to get it right, both in weight and price. They use Marmot’s new MemBrain Strata, in which the half-layer (the .5 protective layer) is printed on the inside of the membrane. The fabric is less expensive to produce, yet it provides the same performance of a conventional 2.5 layer PU laminate. It’s claimed to be less clammy inside and weighs significantly less. The Mica/Crystalline has a basic feature set consisting of two hidden hand pockets and full front water-resistant zip, plus adjustable hood, cuffs, and hem.
The Mountain Hardwear Quark Jacket (9.2 ounces for size L, US$200, and available now) could have been an ultralight favorite. Its innovative Incite fabric is very light and breathable, but its features (drawcords, zippers) are heavier than they need be. The new Marmot Mica/Crystalline Jacket (center, 6.5 ounces, US$130) for spring 2009 gets it right both in weight and price. The Columbia Hotshot for spring 2009 (right, <8 ounces, US$185) has Therma Weld seams that don’t require taping and has vented chest pockets.
The best buys in this category are the GoLite Virga Jacket (8 ounces, US$80) and companion Reed Pant (6 ounces, US$70), and the upcoming Marmot Mica Jacket. The Virga jacket fits well and has a pair of hand pockets. The Reed rain pant is a good choice to go with most any type of rain jacket. As mentioned above, a less breathable rain pant is sufficient because our legs perspire less, and the Reed is as light as they come. Their ankle zips allow them to be pulled on over hiking boots, as long as your feet are not larger than a size twelve. Carol Crooker’s favorite rainwear is "A GoLite Virga prototype – before they added pockets – that’s six ounces. The GoLite Virga kept me warm and dry enough recently on the CDT in Colorado. I hiked in a light rain with the hood over my head and the jacket draped over my shoulders. Tying the sleeves in front of me kept the jacket in place even in breezy conditions and kept my shoulders dry."
Our best buy rainwear favorites are the GoLite Virga Jacket (left), GoLite Reed Pant (center), Sierra Designs Isotope Pant (right), and the upcoming spring 2009 Marmot Mica Jacket (previous center photo).
Overall, we’re seeing a trend in this category away from minimum weight/Spartan rain jackets and toward jackets in the eight-ounce range with an essential feature set. The original Spartan GoLite Virga jacket we saw at summer 2006 weighed just six ounces, but hand pockets were added in the production version to bring the weight up to eight ounces. The original full-featured Sierra Designs Isotope jacket weighed just 4.4 ounces, but it wasn’t storm worthy enough; the current version weighs 5.4 ounces, and it still isn’t storm worthy enough, and the new spring 2009 upgrade will weigh eight ounces. The North Face Diad, our favorite lightweight full-featured jacket in this category, weighs (you guessed it) eight ounces. Eight ounces seems to be the magic number for an adequately durable, storm worthy, ventilated, nicely featured polyurethane laminate rain jacket. If you cut features, including ventilation options, we have The North Face Triumph Anorak (5.4 ounces) as our lightweight favorite.
Rainwear made of 3M Propore (a microporous polypropylene membrane laminated to a nonwoven polypropylene face fabric) is light, inexpensive, baggy, and fragile. Propore is more breathable than Gore-Tex, but not as breathable as eVENT.
The lightest are the RainShield O2 jacket (5.5 ounces, US$30) and the DriDucks jacket (5.2 ounces in large, about US$15). Both garments can be found at substantial discounts online. Frogg Toggs (a three-layer construction of the same components) tends to be heavier and more expensive. An advantage of the RainShield and DriDucks rainwear is they have a slick surface finish that acts like a DWR to shed water, while Frogg Toggs have a fuzzy surface that retains water.
Propore rainwear is light and cheap. Our favorites are the RainShield O2 Jacket (left) and DriDucks Jacket (right).
A distinct disadvantage of Propore is its lack of durability. Janet Reichl finds a new tear in her RainShield jacket after nearly every use. Fortunately it patches easily with duct tape or any type of cloth tape, and with reasonable care a RainShield jacket can last for years. Besides, a rain jacket with lots of patches is really cool! Our experience with Propore pants is they don’t last very long. The knees and seat blow out fairly quickly from kneeling down and from sitting on rough logs and rocks. I recommend using a lightweight nylon rain pant instead, such as the GoLite Reed or Sierra Designs Isotope pant.
The use of Tyvek clothing for rainwear was first brought to my attention by reader John McKay. The specific Tyvek (a spunbonded olefin) I am referring to is type 1443R "soft structure" Tyvek that is used for disposable clothing. This type of Tyvek is soft, waterproof, very durable, highly breathable, and cheap. According to industry information, this type of Tyvek is "six times more breathable than microporous film garment materials." That may be a bit of an overstatement, but Tyvek clothing can be called a "poor man’s eVENT." A hooded full zip Tyvek "jacket" (see below) can weigh as little as three ounces and cost US$5; pants weigh 2.2 ounces and cost about US$2.25. An entire rainsuit can weigh a little over five ounces and cost only a few dollars. I have seam sealed Tyvek clothing (with silicone) and used it for windwear and rainwear with good results.
Tyvek coveralls (left) can be converted into a 3.3 ounce hooded full-zip rain jacket/windshirt by cutting them off below the zipper. Tyvek pants (right) can be used as is and weigh just 2.2 ounces. The cutie is not included.
However, there are some drawbacks. While Tyvek pants can be used without modification, the only way to get a hooded full zip Tyvek jacket is to cut the top off of hooded coveralls. All you have to do is cut the coveralls below the zipper; you don’t need to hem the cut edge because Tyvek doesn’t unravel. Since the zipper doesn’t separate at the bottom, you need to don your new full zip hooded jacket as a pullover. The legs can be converted to rain chaps. A Tyvek shirt and lab coat (which is longer) are available, but they have a snap closure and no hood. They could be used as is for windwear but some modifications would be needed to convert them to decent rainwear. Also, Tyvek clothing needs to be seam sealed to make it waterproof, and the zippers are not the water-resistant type.
It’s hard to find a source of Tyvek clothing that sells it by the piece; most dealers sell it by the case. A good source is MPE Safety Apparel (www.disposable-garments.com), who sell recycled Tyvek clothing by the piece at discount prices.
With some flexibility and creativity, Tyvek clothing can easily be put to use for ultralight backpacking, especially by readers who love a challenge and an opportunity to save some money. I am looking forward to seeing some interesting forum exchanges when readers take this idea and run with it.
Silnylon (silicone impregnated rip-stop nylon) can be effectively used for lightweight rainwear, if the "garment" provides lots of ventilation. Silnylon weighs 1.3 oz/yd2 and is totally waterproof and non-breathable. Thus, any rainwear made of silnylon (or spinnaker cloth) has to be well ventilated.
Our favorite rainwear in this category is diverse. I really like the [http://www.backpackinglight.com/cgi-bin/backpackinglight/six_moon_designs_gatewood_cape_review.html Six Moon Designs Gatewood Cape] (11 ounces, US$135) because it serves as both shelter and rainwear and does it better than a poncho-tarp. It provides an excellent floorless solo shelter when bugs are not a problem, and it doubles as a poncho and pack cover. The AntiGravityGear Poncho Villa (5.5 ounces, US$79) doubles as a vestibule for their Tarptent shelter and a poncho. The poncho will cover a smaller backpack and is best worn with rain pants. Another innovative silnylon rainwear is the Packa (11 ounces, US$110), but it’s a bit too heavy by our standards. Senior Editor Roger Caffin has created his own design that weighs just 6.7 ounces, and Backpacking Light will be publishing a MYOG article on it soon.
Our final selection in this category is the Etowah Outfitters/ULA Equipment Rain Wrap (2.9-3.2 ounces, US$25), which is basically a rain skirt. It goes on and off very quickly, extends down below the knees, and is easy to walk in. (Ok, let’s not get carried away with jokes about what the thru-hiker is wearing under his Rain Wrap!) It suffices very well for lightweight leg rainwear while hiking on trails in warmer weather.
Silnylon rainwear favorites include the Six Moon Designs Gatewood Cape (left), AntiGravityGear Poncho Villa (center), and the Etowah/ULA Equipment Rain Wrap (right).
Ken Knight comments: "I still use an old Montane jacket or even older Stephenson poncho. I suspect that I’m going to give the AGG Poncho Villa a good look along with their shelter. I actually don’t mind a slightly heavier rain jacket, especially if it’s longer in the body and can do double duty as a windshirt without causing me to overheat. This is not something that is easy to achieve, but I don’t like having to carry a windshirt and a raincoat if I can avoid it, more because it’s an extra item to worry about than the weight, which is pretty small."
To summarize my discussion of the various rainwear alternatives, I constructed the following table to compare the pros and cons of each rainwear type.
|Rainwear Type||Light Weight||Packability||Durability||Breathability||Low Cost||Best Season|
|eVENT||2||1||5||5||0||winter, spring, summer, fall|
|GTX-Pro Shell and Performance Shell||0||0||5||4||0||fall, winter|
|GTX-PacLite||3||3||4||4||1||spring, summer, fall|
|PU Laminate||3||3||4||2||2||spring, summer, fall|
|Ratings: 0 = worst of the group; 5 = best of the group
*Although Tyvek gets good ratings, Tyvek clothing requires considerable modification to make it useful for backpacking.
**Although silnylon itself is not breathable, silnylon garments can be constructed to provide adequate ventilation.
New Rainwear Technologies
New technologies to provide us with lightweight breathable rainwear are emerging, albeit slowly. One of the most exciting is Pertex Shield, a new family of durable waterproof-breathable fabrics from Mitsui (who purchased the Pertex technology from Perseverance Mills in 2006). It is based on a polyurethane membrane technology from Mitsui laminated to Pertex face fabrics. The constructions are Shield 02 (2-layer), Shield DS (2.5 layer), and Shield 03 (3-layer), all waterproof-breathable fabrics with excellent breathability and costs lower than either eVENT or Gore-Tex Pro Shell. The two- and three-layer fabrics will provide about 20,000 g/m2/day breathability levels (according to the JIS 1099 B1 standard). That’s pretty respectable compared to eVENT (~27,000 g/m2/day), Gore-Tex XCR (~21,000 g/m2/day), Entrant (about 21,000 g/m2/day), and most polyurethane coatings (5,000 to 15,000 g/m2/day). The lightest versions of Shield will weigh about 2.0 oz/yd2 (two-layer) and 3.0 oz/yd2 (three-layer). Pertex Shield won’t be the lightest, most breathable, or cheapest of the waterproof breathable fabrics, but it could be the right balance of breathability, light weight, and price to win a solid position in the market. The same case can be made for the Toray Entrant waterproof-breathable technology.
The first Pertex Shield rainwear from a major manufacturer is the new Outdoor Research Fanatic Jacket (11.1 ounces for men’s L, US$145). The fabric is very soft, and the jacket has a basic feature set (two high side pockets with core vents, one chest pocket, one inside pocket, water-resistant zippers, and adjustable hood and hem).
A new technology called "Ion Mask," developed by a British company called P2i Ltd, could revolutionize waterproof-breathable clothing and the apparel and footwear industries. The company’s treatment applies a nanotechnology surface treatment to the entire surface of a product which is only nanometers thick. The layer is molecularly bound to the surface of the material and cannot be removed by solvents, chemicals, or "common environmental conditions," making it incredibly durable. The company claims that treated materials (e.g., a garment) display ultra low surface energy values down to one third of that of PTFE (Teflon), making it ultra-slippery and very water repellent, ideal for the outside of a waterproof jacket.
The beauty of Ion Mask is that it applies a "permanent" waterproofing without altering other qualities of the garment, so for example, breathability remains the same. Entire garments, including the zippers, become highly water-repellent. This breakthrough technology, if it really works and is adopted by the outdoor industry, opens the door to potentially limitless applications. Rainwear seems like an ideal application. A three-ounce hooded windshirt can potentially be treated with Ion Mask to transform it into an effective ultralight rain jacket. The same could be true for gloves, hats, and other apparel.
Current DWR treatments are fairly short-lived: they wear off or wash off in a short while, and the garment "wets out," meaning the surface fabric becomes saturated, and water weeps through to the inside. A permanent waterproofing treatment that does not affect breathability would be a major breakthrough, making chemical DWR treatments an antiquated technology.
I inquired around at OR for any applications of Ion Mask, and found it already in use to waterproof footwear. Hi-Tech demonstrated the Ion Mask technology at winter 2007 Outdoor Retailer, and will be introducing light hikers with the technology in spring 2009. For more information on the Ion Mask process and its application to footwear, see my article entitled: 2008 Lightweight Footwear Roundup (to be published soon).
Finally, another waterproofing technology that caught our eye is the Dry Freak Dry Prodigy treatment demonstrated at Outdoor Demo. This fluoro-polymer coating creates a surface that is extremely hydrophobic, causing water to bead up and roll off, as shown in the photo. The result is a "waterproof shirt." Dry Freak claims that the treatment doesn’t modify from outside conditions like a DWR treatment does, and it only loses 10% of its repellency after seventy washings. A "waterproof shirt" is something to ponder; it seems like it would be useful rainwear for light showers in warm weather. The treatment also resists soiling, so the garment stays cleaner. The shirt shown in the photo below weighs about six ounces and costs US$46.
Dry Freak’s Dry Prodigy Water Repellent Technology causes water to bead up on a baselayer-type shirt and roll off. The puddle shown did not wet the fabric after several hours.