The average Ultralight (UL) Down Shirt weighs 167g in men's; 150g in women's. A fair bit lighter than Crux's original Halo Top (235g in the men's 2nd gen. model), which was, I think, the first ultralight down jacket, and the lightest down garment available when it launched in 2008. The Halo now bears the tagline 'Unique when launched, Halo is now our most copied product.' Ultralight down jackets are now becoming more common, and it's only fair to point out that Crux are launching their new lighter Pico top (170g) this autumn.
Things have moved on at Patagonia, too: the UL Down Shirt is now the lightest of three siblings. There's also the UL Down Jacket (full-zip, hoodless: 235g in men's) and the UL Down Hoody, (full-zip, hooded: 264g). I went for the UL Down Jacket. I felt it offered greater versatility for a few extra grams (235g is about the weight of four regular sized Mars bars to give you an idea of how light it is) but didn't want the extra bulk of a hood. I was particularly concerned about not getting the jacket wet or sweaty, as it is down, and figured a full-zip would allow more venting and make getting it on and off easier, both of which would reduce the likelihood of this happening.
What's it for?
A down jacket designed to work as both a stand alone insulation piece (in spring and summer) but also a midlayer (in autumn and winter), it's a potentially very versatile jacket that's useful year round. I've used it as a mid layer for autumn/winter walking, climbing and skiing, and as a stand alone chuck on layer for spring/summer skiing, walking and belaying. The advantage of an ultralight down jacket over a typical synthetic insulated jacket is obvious. Compared to a synthetic puff - let's say Patagonia's popular Nano Puff - the UL Down Jacket is much warmer and a lot lighter (the Nano Puff is 354g in the men's full zip, hoodless version) for similar bulk. See photo below for how thin it is.
Avoiding getting it wet
However, the 'down'side is obvious too: it's not at all versatile if it gets wet or sweaty and the fluff shrivels up. I was doubtful when I packed it for a week of Scottish
Winter back in driech February, and also packed a synthetic puff
"It weighs about the same as four regular sized Mars bars"
The weather treated me to ideal testing conditions over the week - variously muggy and damp, freezing, wet and white out, with some nice blasts of spindrift in places - but I found I had instantly hit the sweet spot with a layering system of long-sleeved Merino base layer, the UL Down Jacket and a Polartec NeoShell hard shell over the top. I didn't get sweaty, and was pretty much the perfect temperature all day while moving, so I didn't take my hard shell off either, thereby avoiding getting the UL Down Jacket wet, too. Perhaps this is in part owing to the super breathability of NeoShell, a new fabric I really like, see this review; or perhaps partly because this hard shell is still quite new, so working at its best. Or perhaps I've just been lucky, or not working hard enough.
Warmth and comfort
I was worried I'd get too hot and claustrophobic wearing down as a midlayer, but in fact I've always been super comfortable in it. As it's so light it feels much more airy and unrestrictive than a synthetic insulated midlayer; it's also a lot less bulky than a synthetic puff that would offer comparable warmth. I do feel the cold though. If I stopped up high in winter I usually added a Rab Neutrino over the top to keep me warm.
"The UL Down Jacket also has better weather resistance than any other Patagonia insulation so far"
Patagonia's previous lightest weight down piece was the Down Sweater (343g in men's). Despite being leaner, I think the UL Down Jacket feels similar in warmth. It's slimmer cut, so perhaps more efficient at keeping heat in, and the shell fabric is more weather resistant, too (see below). The down inside is high quality - 800-fill power premium European goose down - and held in place by narrow sewn-through channels, which apparently allowed Patagonia to use less down in achieving the warmth they wanted.
As a stand alone layer
Moving into spring and summer, the UL Down Jacket proved perfect for chucking in my bag when skiing in warmer weather on a Chamonix trip, and pulling on in shady areas or for lunch stops. I've also worn it loads as a summer belay jacket - it feels great at the end of the day when the sun dips and you're a bit chilly and tired! - also for summer campsite wear and so on. It's just ideal in spring and summer if you don't like to be cold but don't want to carry anything cumbersome. The only thing I have to remember is to bring some kind of waterproof shell if I'm out all day. The only other thing I'd say is that the really lightweight face fabric feels a bit plasticky, so not great for next to the skin wear.
Weather resistance obviously comes into play when wearing the jacket on its own. The UL Down Jacket has better weather resistance than any other Patagonia insulation so far. The special edition nylon ripstop shell fabric used apparently has half the weight and twice the strength of Patagonia's other down shell fabrics (27g/m2 nylon). It's actually so thin you can see the feathers inside, which some people have admired, and others have thought looks a bit weird!
All this is topped off with a coating of Patagonia's excellent Deluge DWR (durable water repellent) finish, which I've always found lasts very well. Patagonia recommend using a mild dish soap for spot cleaning and to be sure to thoroughly rinse all the soap off the material with lukewarm water. I've been wearing it for a year, am not particularly careful with gear, and seem to have easily avoided getting it damp.
There aren't many on this lightweight piece. The pocket arrangement is simple - two handwarmers and a zipped chest pocket; while a hem drawcord helps keep heat in further.
Other than you have to avoid getting it wet, and the minor criticisms of the fabric feeling plasticky next to the skin, and you can see the feathers through it, which you might find aesthetically challenging, my only other criticism is that it's good but it's pricey. Compared to Patagonia's synthetic Nano Puff (£175), and considering you can get a full on down jacket like the Rab Neutrino for under £200... However, I'm expecting it to last me ages, especially as Patagonia's customer service is excellent, and they are great at repairing things!
A very simple jacket, lean and clean cut, which I found offered the ideal amount of warmth and comfort as both a winter midlayer and a summer belay jacket.