by Alan Dixon and Ryan Jordan | 2003-07-01 03:00:00-06
|Soft shells like the Cloudveil Rodeo Jacket (shown here) are becoming increasingly popular among backpackers and alpinists alike.|
Given only 60 seconds to choose our clothing for a hike or climb, we would likely choose a soft shell jacket and pants first, and build the rest of layering system around those core garments.
Combinations of soft shell garments, especially when layered over next-to-skin wicking garments, offer a wide enough comfort range to deal with most inclement environmental conditions we are likely to face, including sun, heat, cold, wind, light rain, sleet, snow, brush, sharp rocks, and mosquitoes. The breathability of soft shell fabrics means that we can remain comfortable under a wider variety of conditions than traditional coated or laminated "hard shell" fabrics.
We still find utility in waterproof-breathable (“hard shell”) garments for cold, heavy precipitation, as we find in the spring and early summer in the Rockies and Sierras (or year round in the Pacific Northwest). But for most conditions, we prefer to wear garments made with soft shell fabrics.
|"A soft shell garment is a piece of clothing designed to be worn as an outer shell layer made with a breathable, but weather-resistant fabric, and designed to replace a 'hard shell' ... for most conditions."|
Patagonia and Cloudveil, the outdoor industry's two most vocal proponents of soft shell technology, disagree on the definition of a soft shell. There is quite a lot of pride at stake in this somewhat ridiculous terminology war, simply because these two companies have advanced soft shell garment design more than anyone. However, to find some common ground, we’d rather not fuel the confusion and simply say this:
A soft shell garment is a piece of clothing designed to be worn as an outer shell layer made with a breathable, but weather-resistant fabric, and designed to replace a “hard shell” (e.g., a garment made with a waterproof-breathable or -nonbreathable fabric) for most conditions.
Based on this definition, one might find that an eight dollar polyester disco shirt from your local Target store suits your needs as well as a $300 stretch woven jacket. Hey, it’s not a pretty picture for the outdoor industry, but welcome to reality. But inherent in that reality is the realization that a disco shirt can only take you so far, and there are scores of other fabrics more suitable for high-performance clothing. We take a closer look at two families of those fabrics herein – silicone-encapsulated wovens, and stretch-wovens.
The breathability of a soft shell fabric will almost always surpass that of the best waterproof breathable garments (although as technology continues to advance, the gap is expected to be narrowed), so soft shells tend to be more comfortable over a broader range of temperature and exertion than hard shells. In addition, they typically compact better (this is not a hard and fast rule, as most stretchwovens are notoriously bulky), are quieter, and dry more rapidly than hard shells.
In heavy rain, there are two keys to staying warm and comfortable in a soft shell. First, soft shell garments shed light precipitation, so even if some of the precipitation eventually does come through the garment, the vast majority of it should bead and run off the fabric (but be sure to keep the DWR finish on the soft shell refreshed in order to take advantage of this feature). Second, in conjunction with a good base layer, moisture that does migrate can often be evaporated if your activity level is high enough. And yes - you guessed it - soft shells (at least in inclement conditions) are targeted towards higher activity levels. If you are just ambling down an easy trail or drinking cowboy coffee around the campfire, you might do better with a hard shell. But for anyone who has drenched themselves with sweat in a hard shell while pushing hard in the backcountry, the breathability and temperature regulation of soft shells are a blessing.
We’ve divided soft shell fabrics into three categories: stretchwovens, silicone-encapsulated, and hybrids.
Stretchwovens. Stretchwoven fabrics include Schoeller Dynamic, Ibex Climawool Lite, and Cloudveil Inertia. Garments made with these fabrics tend to be the most breathable and durable of the soft shell families. Their key feature is the ability to stretch and accommodate the body movements of an airport runway flagger, or, say, a mountain climber. The important result from this is that the garment can be made a little trimmer than a non-stretch garment, which reduces bulk. Thus, the garment is less likely to snag on brush or flap in the wind, and it tends to be more effective at breathing moisture generated by activity (there is a downside to a trim fit – ventilation is compromised).
The stretch can originate from two sources: mechanical stretch or fiber stretch. Mechanical stretch is stretch that is built into the woven fiber structure, much like the stretch you find in fishnet underwear, even though the fibers themselves possess little or no stretch. Fiber stretch results from blending fibers like Lycra or Spandex into the material. Proponents of mechanical stretch fabrics claim that the removal of stretch fibers (1) reduces fabric weight for similar performance, (2) reduces water absorption by the fabric (stretch fibers tend to be more water absorbent due to their more porous fiber structure), and (3) increases durability over fabrics using stretch fibers. We’ve found the increased durability to be true on a 50,000-cycle tension machine in the lab, but even for heavy field use for several years, we’ve yet to see a stretchwoven fabric “sag” from overuse. So, be cautious of more marketing hype than you need.
Manufacturers of stretchwovens are quick to tell you that their fabrics possess a unique type of water resistance that is inherent in the fabric structure and is not dependent on a chemical fiber treatment for water resistance (which, they are quick to point out, can wash or wear out, despite the fact that nearly every stretchwoven fabric on the market in the U.S. has been DWR-treated). They go on to say that the surface of the fabric is woven in such a way that the hydrophobic face structure has a significant topography (peaks and valleys) rather than being completely flat like a typical rain shell. The net effect is that there is less surface area in contact with a water droplet that comes to rest on the fabric, which results in a lower surface tension force on the droplet, making it less likely that the droplet will collapse and wick into (i.e. wet out) the fabric. Then they take the garment to the store bathroom and show you all this neat stuff as they run it under water. Lo and behold, magic happens and not a single drop of water leaks through.
|"...all of a sudden, you find yourself soaking wet in a light rain and those beads of water that were terrified of the fabric at the store are now ripping their way through the garment like an anopholene whore through open weave mesh. What the heck?"|
The actual field scenario goes something more like this. You bring your $250 stretchwoven jacket home, take it out on your first summertime weeklong backpacking trip, and exclaim that it’s the best thing since peanut butter. A few months of heavy use go by (a few years perhaps for those of you that are more accustomed to armchair adventure) and all of a sudden, you find yourself soaking wet in a light rain and those beads of water that were terrified of the fabric at the store are now ripping their way through the garment like an anopholene whore through open weave mesh. What the heck?
The DWR finish probably washed out when you did your laundry (the likely scenario). Or got mucked up with dirt, grime, and sweat. What can you do? Grab some Scotchguard, Rain-X, or Revivex and restore it. You’ll be back in the saddle before you know it.
So, remember these key principles: (1) DWR finishes on new products can be really good, (2) manufacturers, designers, marketers, and store employees are pretty suave about highlighting the in-store performance of a new garment, and (3) these fabrics aren’t magic. Spend the cash and time to keep the DWR fresh, and you’ll find the utility of a stretchwoven to be very appealing.
Many stretchwovens also provide some measure of insulation (during the summer, we often leave our long underwear bottoms at home when we take stretch-woven pants). This results from the fact that stretchwovens are thicker, have rougher surfaces and interstices, and are able to trap more insulating air. The downside to this type of construction, however, is that rain-soaked stretchwovens absorb more water than silicone encapsulated soft shells, and will require more time to dry out, whether you are hanging it under your tarp or drying with body heat while wearing it.
The biggest downside of stretchwovens for lightweight backpacking is that they are heavier than a similar garment made with other soft shell fabrics. The very lightest stretchwoven nylon zip-T shirts on the market currently remain over 8 ounces, with the lightest jackets weighing 14 oz or more. Thus, if the stretchwoven shell is going to remain in your pack for most of the trip, you might be better off with a garment made with a lighter, more compact soft shell fabric.
Silicone Encapsulated. Silicone encapsulated microfiber fabrics include Nextex EPIC, Cloudveil Cirrus, and Patagona Encapsil. Garments made with these fabrics tend to be lighter, more wind and water resistant, and less water-absorptive that stretchwovens, at the sacrifice of some breathability (and insulation). They are also more fragile than stretchwovens and may not be as appropriate for bushwacking or rock scrambling. Their biggest advantage is their potential to be very light and stuff to a very small size. For example, one manufacturer makes a full-length jacket using EPIC that includes a generous hood, full zip, mesh-backed torso pockets, and pit zips at a weight of only nine ounces. Silicone-encapsulated shirts can weight as little as four ounces.
The most common silicone encapsulated fabric is Nextec EPIC. EPIC depends on the silicone encapsulation of each fiber to repel water and to close spaces between fibers. Since the encapsulation does not completely close spaces between the fibers, the fabric still breathes. After encapsulation, EPIC is more water resistant but not as breathable as an untreated microfiber fabric or a stretch-woven fabric. According to unverified sources, EPIC is water and wind resistant to 4 lbs/sq. in. Again, manufacturers of silicone encapsulated fabrics like to tout the perception that water resistance is a permanent feature of the fabric and can’t be washed out like a DWR. However, if the fabric becomes soiled (from grease, dirt, and sweat), look out – silicone encapsulated fabrics let plenty of water wick through and it thus loses its water resistance. In addition, although silicone encapsulated fabric garments are good for light rain, sleet, and snow, they still are not going to protect you in sustained rain. Their real strength is the combination of light fabric fiber encapsulation – this means they absorb less water into the fabric structure and dry very quickly. This is a significant benefit in the backcountry when you are finally seeking shelter after a long day of rain. You can literally “shake out” a silicone encapsulated fabric garment, hang it in your tent or under your tarp, and it will probably be dry to the touch in less than a few hours.
Hybrids: Some garments are constructed with soft shell type fabrics (like Schoeller Dynamic) with the addition of hard shell (waterproof-breathable) fabric in key areas like the upper arms and hood – areas most likely to saturate and leak during a hard rain. Apparel falling into this new soft/hard-shell category has the most potential to replace fully waterproof-breathable raingear in your backpack. Could a hybrid provide the construction basis for the ideal soft shell? Consider a jacket that uses a waterproof-breathable yoke and hood with a silicone-encapsulated body, with both fabrics less than 2.0 oz/sq.yd. A full-featured jacket could be manufactured at a weight of less than nine ounces. We're still waiting.
Soft shells are not the cure all for backcountry shell comfort. But the addition of a stretchwoven or silicone-encapsulated garment to your clothing ensemble has the ability to significantly increase the comfort range of your clothing system.
"Soft Shells: The Real Story," by Alan Dixon and Ryan Jordan. BackpackingLight.com (ISSN 1537-0364).
http://backpackinglight.com/cgi-bin/backpackinglight/00103.html, 2003-07-01 03:00:00-06.