Patagonia DAS Light Pants

The “micro puff” of pants: packable, lightweight, and practical

Drew Thayer

If you’ve ever worn a pair of thick, pillowy down pants on a cold winter day, you have felt a wee sliver of heaven. However, voluminous down pants are often not practical for what most of us do – they tend to be expensive, they are hard to compress into a backpack without additional compression bags/straps, and they carry the liabilities of down, losing their warmth as they get wet.

The thing about big, bulky pieces of clothing is that when the rubber hits the road of loading up my pack for an excursion, the big stuff almost never makes it in. These DAS Light pants are like a “micro puff” jacket for your legs: a bare-bones synthetic insulation pant that packs down to a small volume – despite full separating zippers! – that ends up being a practical choice for winter camping, skiing, and light alpinism in the lower 48. 

Staying warm on a frigid November morning at Indian Creek in the Patagonia DAS Light Pants and Hoody. These are great, practical synthetic insulation pieces that are close to wind proof, nice for the cutting breeze on those desert mornings.

Weight and packability

These pants only weigh 11 oz (men’s medium) – that’s about the same as a semi-lightweight hardshell jacket with pit zips, a Micro Puff jacket, or an R1 fleece hoody. The PlumaFill insulation doesn’t fill its baffles as down does; it sits in them more like a sheet, allowing these pants to be rolled up nicely to shove down the side of a backpack. 

Build, fabric, and performance.

The Patagonia DAS Light Pants can accurately be thought of as a Micro Puff wrapped around your legs. These pants are made of the same materials as the DAS Light Belay Hoody (review HERE), essentially a climbing-specific version of the popular Micro Puff Hoody with slightly more robust shell material.

The DAS Light line is wrapped in ​​0.8-oz 10-denier Pertex® Quantum Pro, which is a bit more windproof than the Pertex® Quantum 0.8-oz 10-denier NetPlus used on the Micro Puff. All three garments weigh in close to 11 oz in men’s medium and have a similar amount of bulk, so if you own one, you can picture how the others will fit in your pack.

Nothing makes ice cragging more civilized like a pair of puffy pants. (Except for maybe a thermos of coffee?). The Patagonia DAS Light Pants have full separating zips, facilitating easy donning and removal over crampons and harness.

These insulation pieces also share the same fill, 65-gram PlumaFill insulation, which in my experience, works really well at this weight. It’s a laminar sheet of fibers that lofts a centimeter or so, mimicking down. While I don’t think synthetic insulation tends to work in higher-loft applications (i.e., jackets trying to be warmer), it’s very effective in this “micro puff weight” kind of layer, offering excellent warmth-to-weight in a material that will maintain most of its thermal properties when it gets wet. This is a good choice of material for pants, which tend to get sat in, dripped on, laid on the ground, etc. 

Pertex Quantum Pro is not waterproof, but it’s quite windproof and will repel a light drizzle or wet spring snow. If you’re getting dripped on in some heinous icy belay, these will keep you dry enough, and they won’t soak up much water – you can just wring them out and shove them back in the pack if you’re getting wet. 

Style, fit, and usability

DAS Light pants are cut to a relatively slim fit; folks with beefy thighs might want to size up. I’m 6’ tall and pretty skinny with long legs, and a size medium fits me well. As over-pants, they are sized up enough to fit over other pants (typically two layers – thermals and a pair of hard or soft shell pants), but just enough – these are not roomy. This hasn’t been a problem for me since I’m mostly standing around or sitting around the campfire while wearing them. I’ve also hiked 20 minutes to an ice crag while wearing these, and they didn’t encumber my movement, but YMMV depending on your build and the pant size. 

The most exciting feature of these pants (other than the insulation) is the full separating zippers! What does this mean? You can take these on and off while wearing crampons or ski boots (or even skis, for that matter), which for me, is the whole point of owning insulated pants… they’re for adding some civility to those bone-chilling belays on ice climbs. Once you get the hang of it, it’s pretty easy to put them on in 20 seconds or so, and voila… happy legs.

I will call out that for a climbing-specific piece designed to be worn by ice climbers, Patagonia could have made the ankle cuffs a bit less slim. I cannot close them around my ankles when wearing mountain boots and soft-shell pants. This doesn’t really matter – they’re not going to unzip themselves – but it’s a silly oversight. 

C’mon now, the ankle cuffs on these pants should be a little wider so I can close them around my boots. Not a big deal, but a little sloppy.

Bottom Line

Big, voluminous down pants are awesome. They will also never make it into my climbing pack when push comes to shove. The DAS Light Pants are a practical insulation pants with full separating zips that allow ice climbers, skiers, and alpinists to bring along the creature comforts of warm legs in a packable 11 oz package.

The material is fairly durable and weatherproof for its weight, but these should be treated as lightweight gear (abuse with care). These pants are not appropriately warm to climb Mt Denali but will be adequate for most winter climbing in the continental US (comfort is relative, of course).

They’re also made of recycled material, which is awesome! I’m really happy with these pants and am already getting some great use out of them this season, though I’ll note the price point is a little high at $299. Heavier, warmer pants are available in the low $200s, like Black Diamond Stance pants (synthetic, burly) and Rab Argon pants (down, similar weight). So while I wouldn’t recommend buying these for winter camping or occasional use, the Patagonia craftsmanship and high-quality materials might be worth it if you’re into winter alpinism. Stay warm.

Drew Thayer