Ultralight fabric packs are easier to come by these days. It’s time to explore some of the UL materials in use.
Ultralight fabrics. They’re so hot right now. Ultralight fabrics. With a head spinning array of fabrics on offer, we consult those with more knowledge to learn more about the UL fabric landscape and their application in backpacks.
History Repeats Itself-Packs
Let’s take the time machine way, way back. Ötzi the Iceman, who crisscrossed the Alps, is said to have carried a pack—it looks like an iterative form of a frame pack. Estimates pin down Ötzi’s ramblings at roughly 5000 years ago. Although rudimentary in design, we can assume Ötzi’s pack allowed him to haul more weight more efficiently had he had no pack.
Despite our reliance on backpacks, still, thousands of years later, a Colin Haley quote sheds light on pack design over the years—”it’s 2000 year old technology…amazing how pack manufacturers can still screw it up.” Following along with the socials the past few months, it might seem Haley’s 2000 year wait for a more perfect pack is over.
This is all to say that packs have improved over time. And the market’s diversity means you should be able to find a pack that suits your peculiarities. I prefer a side zip and roll top for main compartment access. I prefer no frame and just a simple foam back panel for comfort and structure to carry loads up to, say, ~20 pounds. I now use packs with no load lifters—both for day trips and multi-day traverses—with no complaints.
My 70L multi-day pack weighs ~1150g. My single-day ski pack weighs ~625g. I like these packs because they are simple and meet my needs for stowing and carrying. And they are light. At these weights, I’m still not compromising on comfort and features (except for wanting full side zip access on the 70L pack).
Part of the overall reduction in a pack’s overall pack weight, generally, is due to the use of lighter fabrics that are often more durable than more traditional pack fabrics.
The birth of a new Apocalypse Equipment pack: blue fabric is Ultragrid and the silver fabric Ultra 200. Both fabrics are ultralight fabrics from Challenge Outdoor.
Pack Fabrics
Here we are—pack fabrics. In recent years, thanks to the ultralight backpacking scene, we have many high-performance, lightweight fabrics to choose from. But keeping up with R&D trends and off-the-shelf lightweight fabric options is dizzying. We’ll run through some of the main fabrics currently in play and get thoughts from pack makers Gavin Hess from Apocalypse Equipment (and THR) and Matt Zia from Otterbody Threadworks. First, some background.
Let’s define the word denier. Thank you, Wiki: “A unit of measure for the linear mass density of fibers is the mass in grams per 9,000 metres of the fiber. The denier is based on a natural reference: a single strand of silk is approximately one denier.”
Who makes this stuff?
Dyneema
Dyneema: The brand name of the lightweight, high-strength fiber and fabrics. Formerly known as Cuben fiber, Dyneema is the default name for ultra-high-molecular-weight polyethylene (UHMWPE). UHMWPE is made by several companies other than Dyneema. Dyneema, however, has unique capabilities in the manufacturing of bio-based Dyneema fiber, using tree pulp, as well as the ability to make super low denier Dyneema yarns.
DCF- Dyneema Composite Fabric. DCF has a non-woven component. Non-woven Dyneema fibers sandwiched between mylar films.
DCH- Dyneema Composite Hybrid is a mylar film, then a layer of non-woven Dyneema, with a final outer layer that replaces the mylar layer with 50D or 150D woven polyester.
DCHW- Dyneema Composite Hybrid Woven has the same makeup as DCH, except the final layer is a 100% woven Dyneema face fabric, not the 50D or 150D woven polyester.
X-Pac fabric swatches.
X-Pac
X-Pac: You likely know X-Pac fabric: it has cool-looking Xs woven into the fabric. X-Pac is a subsidiary of Dimension Polyant. X-Pac has been around in some form or another for almost 20 years.
X4: This fabric is a four-layer laminate. Top to bottom, we have a face fabric, then an X-ply, a polyester film layer, and finally, a white woven backer—iterations of X4 fabric offer different face fabric options.
X3: The X3, as the name implies, offers a three-layer option. It runs as follows—face fabric, X-Ply, and a polyester film backing. Again, X3 comes in several versions, each with a different face fabric.
Challenge Sailcloth
Challenge Sailcloth: These folks own Challenge Outdoor, which produces EcoPak and Ultra fabrics. They are the “new kid on the block,” launching their outdoor fabric line in 2020, and are known for their widespread use of recycled polyester and nylon in their fabrics.
ECOPak has similar makeups to X-Pac, with most products featuring a 100% recycled polyester construction.
Fabric spec sheet from Challenge Outdoor.
Ultra X: 70% UHMWPE (called Ultra fiber), 30% polyester face fabric. Produced in 100, 200, 400 and 800 denier iterations. This fabric has been updated to include an X-grid for dimensional stability and PET laminated backer, this is similar to the DCHW listed below.
Ultra: Same as above, but no X-Grid and thinner PET film.
Ultra Tx: Same as Ultra X, but adds a 50D polyester ripstop as the backing (no exposed film).
There are also ultralight, waterproof fabrics like Silnylon: a woven nylon fabric (often in a ripstop grid) impregnated or coated with silicon. Or, you can go the route of the tried and true packcloth like Cordura®—which is generally a PU-coated nylon fabric. Cheaper than the fabrics mentioned above, these options often compromise either weight, durability, or weatherproofing. But we are here to focus on the newer, high-tech laminate pack fabrics that aim to combine high-level durability and weatherproofing with low weight.
A Bozeman made Otterbody Threadworks pack constructed with UL fabrics.
The UL Fabric Conversation
Gavin: There’s only one fabric that Matt and I, as small backpack makers, don’t have access to at this point—I think Hyperlite is the only one still using it. I believe Hyperlite calls it DCHW, and they use it on the sides of some packs, where, for example, one A-frame carries as on some of their ski packs. They used to make full packs out of it, which is pretty badass. Cilogear used to use something similar, but most companies have moved away from it as it is exorbitantly expensive (north of $100/yard).
But that’s a 100% Dyneema face fabric, so it’s a woven Dyneema fiber face fabric, and then it has a non-woven Dyneema layer and mylar laminate backer to make it waterproof. The generic fabric, when somebody talks about Dyneema as a brand name pack fabric, they’re talking about what I think is colloquially known as DCH, or a Dyneema Composite Fabric Hybrid.
That is a laminate non-woven Dyneema layer and then a polyester face fabric. I think Matt would agree with me in saying that while DCH has the branding of Dyneema, it lacks a lot of the performance of the 100% Dyneema face fabric because the main things a ski or climbing pack gains with the Dyneema are abrasion and cut resistance. And by not having that in the face fabric. It mostly eliminates that benefit. I’d say, in my experience, the Dyneema fabrics perform decently well until they don’t, and then they come in contact with something sharp, whether it be a burr on a ski edge or a crampon, and then it slices like butter.
Matt: Yeah, the other thing that’s sort of interesting to notice about the Dyneema, or I guess DCF in general, is that it doesn’t hold up that well to repeated stress over a single point. So I have an old Hyperlite ice pack in the roll top where you’re rolling the same piece of fabric the same way every single time you open and close the pack, and the inside just fully delaminates, and I end up fixing my $500 pack with a roll of duct tape.
Gavin: Is that a DCHW or, the older school Hyperlite pack?
Matt: Yeah. I think that that fabric is much better suited to spots that aren’t seeing repeated wear on the same point. So, on the front of a pack, for example, that is crushed repeatedly, dragged up stuff, and often in various ways, but it’s not getting repeatedly rolled and folded on the same spot, it works.
Gavin: Taking a step back, in the broader lightweight pack market, we’re talking laminate fabrics. Right now everything we’re talking about is laminate, and I think, correct me if I’m wrong, that everything you’re using at Otterbody, and everything I’m using at Apocalypse is in the laminate category.
And when we hear sailcloth mentioned, we should note that sailcloth companies generally make the pack fabrics, but they’re not sailcloth fabrics—this is an important distinction as there’s not a crossover application where a backpack fabric is also being used in racing sails. It’s more that the lamination technology and maybe components are transferable, but generally not the whole product. You’re not seeing Ultra-400 racing sails.
Matt: This broad category of laminate fabrics is, by and large, what we’re talking about. On some reinforcement areas, on some specific packs I build, I’ll still use ballistic Cordura or some sort of ripstop single layer, maybe with a coating on it for waterproofness.
Gavin: We’re also both using Ultragrid, which is a Dyneema ripstop on a traditional coated nylon fabric. It’s a good example of a newer fabric as it’s only a single layer of woven cloth, and then it has a polyurethane coating for waterproofing rather than being multiple layers, or what we are referring to as a laminate.
Matt: The number of pack makers using laminate fabric is quite small in the grand scheme of things—if you go to Black Diamond, Osprey, or Mystery Ranch, the vast majority of backpacks are made using a traditional woven pack cloth fabric, whether it’s Cordura, a ripstop nylon, or something like that, the vast majority of packs are using some variation thereof.
Gavin: Aside from a few specific examples, Arc’teryx has their AC 2, which is a TPU laminate, really cool fabric that they stopped using in their climbing packs. They still use it in some commuter packs. It really is one of the best fabrics out there, but they stopped making their Alpha line of packs with it.
There are only really three main makers of laminate pack fabrics: there’s Dyneema, which we talked about. And then there’s Challenge Sailcloth and X-Pac, which is owned by Dimension Polyant—both are sailcloth manufacturers.
Those are the big three. And the outdoor fabric sections of both Dimension Poly and Challenge were started by this gentleman, Hale Walcoff, who unfortunately recently passed away. It’s a wild thing—this whole market really started by one guy.
He moved from Dimension Polyant over to Challenge and came out with these woven UHMWPE-faced Ultra fabrics, which are kind of all the rage right now. From more mainstream manufacturers, I think Black Diamond is coming out with a fast-packing pack or something that uses Ultra fabrics. Within the small ski and climbing pack brands, Alpine Luddites and Cilogear use a variety of Ultra fabrics, as does Alpine Threadworks. However, amongst the handcrafted pack market, he’s sort of a holdout on using some 500 D or 1000 D Cordura fabrics, but I think he’s now offering Ultra TX as well.
That’s the state of the fabric market right now. But it’s changing fast. I jumped in early on some of the initial Ultra fabrics. And they weren’t perfect as far as the lamination quality. Over the last two years, I’ve had to repair some delamination in high-stress areas. But those fabrics have been updated. Matt and I have switched many of our fabrics over to what they call Ultra TX, that, rather than being a shiny laminated mylar inner surface, they actually have a woven backer which increases the lamination integrity and stitch holding.
Lamination strength seems to be the crux of a lot of these fabric and pack companies right now, Dyneema is so slippery that it’s really hard to laminate because a normal adhesive that would work for polyester or nylon just doesn’t stick as well to Dyneema.
