When it comes to the gear needed for backcountry endeavors, there is almost always a concession. Maybe your rain jacket is the most repellent garment you own, but it doesn’t breathe well and leaves you sweaty. Or perhaps your favorite hiking boots have sticky-as-glue traction but feel like bricks on your feet. When it comes to down jackets, chances are good you’re evaluating the warmth-to-weight ratio: What level of toastiness will you get for how easy it is to squish the jacket inside your backpack?
That’s where the Rab Mythic G Down Jacket shines as arguably the warmest packable puffer I’ve worn in nearly a decade. Over the last six months, I’ve taken the Mythic G everywhere from weekend bikepacking trips to high alpine backpacking adventures and dead-of-winter ski touring escapades with temperatures in the single digits. It’s become my can-do-anything puffer that I rely on to keep me safe and warm.
If you are in the market for an ultra-lightweight and packable puffy, read on for why the Rab Mythic G is my absolute favorite.
Thanks to 4.5 ounces of down (in a men’s medium), a heat-reflective lining and a hip-length fit, the Mythic G is an ultra-warm puffy built for outdoor adventures like mountaineering, backpacking, hiking, ski touring or climbing.
With a whopping 1,000 fill power and stitch-through construction, the Mythic G clocks in at less than 9 ounces — that’s a cup of milk — and packs down to the size of a Nalgene bottle in the included stuff sack.
What I liked about
I live in the mountains outside of Aspen, Colorado, so mountain recreation isn’t just an occasional activity for my family: It’s our year-round lifestyle. We ski in the winter and hike, backpack, camp, fish and bike in the spring, summer and fall. Oftentimes, I’m outside playing before work on a Tuesday, after school pickup on a Thursday and all weekend with my husband and daughter. That’s why I was so stoked to find an all-around ultra-light and ultra-warm puffy like the Mythic G. It’s become my one-stop-shop jacket for all my adventures.
Warmer than a toaster oven
We wear puffy jackets because we need to stay warm, and the Rab Mythic G is arguably the warmest puffer in my closet — and I have a lot. For starters, Rab lined the jacket with its Thermo Ionic Lining Technology (TILT), a reflective lining inside the puffer that looks a lot like the metallic fabric from an emergency solar blanket. That’s because it is metallic; the fibers are coated with vaporized metal particles. Taking a cue from space, this TILT lining reflects your body’s radiant heat back at you to keep you warm without compromising breathability or adding extra weight.
Of course, that’s a lot of fancy language but I am convinced it works. Over the past six months, I’ve worn the Mythic G on dozens of outdoor adventures and it keeps me warmer than other comparable down jackets. Contrary to popular belief, fill power doesn’t necessarily equate to more warmth (more on that below). Instead, it’s a reflection of the quality of down. For warmth, you also want to pay attention to how much down is packed inside the jacket. In this case, the Mythic G is filled with 4.5 ounces of 1,000-fill-power down (in a men’s medium). This is a lot of down for a jacket as light as this, and that combined with the TILT lining is why the Mythic G has become my favorite for ski touring.
During a recent day on skis, temps were in the single digits and it was a bit breezy with light snow falling. Once we hit our turnaround point to transition into downhill mode, I immediately felt my core temperature drop. I’m notoriously cold (my husband’s wedding vows included promises to be my human heater), so this is pretty normal. But this time, I scrambled to throw on the Mythic G while ripping off my skins and buckling my boots. It immediately warmed me up — and made me very grateful for outdoor gear that allows me to do what I love.
Lighter than (a bucket of) feathers
So, here’s the real deal with fill power. It’s a number that represents the volume (in cubic inches) taken up by an ounce of down. This means an ounce of 650-fill-power down would take up 650 cubic inches of space while an ounce of 850-fill-power down would take up 850 cubic inches.
Here’s the catch: Down creates warmth by trapping heat in the air space between all the fluff. A 1,000-fill-power down takes up more volume — and creates more air space — than a 650-fill-power down. This means an ounce of each fill power should be equally warm. However, the 1,000-fill-power jacket (like the Mythic G) will be a lot lighter since it reaches the same warmth with more air and less dense down.
That’s the beauty of this Rab puffer: its warmth-to-weight ratio. As we mentioned above, it’s absurdly warm, but it doesn’t come with a weight penalty. And all that air space in the 1,000-fill-power down that keeps it light also makes it supremely packable. After all, you can fold and crease and smush air all day long — it’s never going to become bulky. In this case, Rab includes a small stuff sack that you can pack the jacket into, but I’ll admit that I quickly lost it. No worries, though, because the entire puffy fits inside its own pocket, making it super easy to throw inside a backpack in case of emergencies.
As an added bonus, Rab uses stitch-through construction — sewing the top and bottom lining together to create the baffle — which saves even more weight.
Useful features
The Mythic G doesn’t have a lot of bells and whistles. But it does have a few useful features that are worth noting.
In particular, I am a big fan of the hood. It’s filled with down so it actually keeps you warm rather than just holding on to your hair. And the sides have an elastic band, so it’s easy to stretch the hood over a helmet, hat or even a gigantic ponytail. I also like the stiffened visor that runs along the top. It’s bendable, so I’d often crease it in the middle to create a small peak that keeps moisture away from my face.
The drawstring running through the back hem is also handy. I didn’t use it often, but during one particularly blustery day, I cinched the drawstring down so that it snugged up against my backside. It was a little tweak, but it trapped a lot more warmth inside and prevented bone-chilling winds from sneaking by.
Full transparency for sustainability
The last few years have brought a lot of sustainability conversations into the outdoor industry, and I really appreciate how Rab is handling the topic of transparency. When you look at the Mythic G online, you can scroll down and see a small chart that looks a lot like the nutrition label on a box of crackers. This is where the brand breaks down sustainability initiatives like recycled content and fluorocarbon (PFAS) content.
It may sound simple at first, but this is more information than you will get by reading the label inside the jacket. Not only do the labels share exactly how much of the material is recycled but they break it down so you know which pieces are recycled and which are not. The same rule applies for fluorocarbons. For the Mythic G, you can easily see that there are no fluorocarbons anywhere on the jacket other than the zipper. As folks become more interested in supporting transparency, I think this type of labeling will be important.
What I didn’t like about it
Remember how I said there are always concessions with outdoor gear? It’s true. And when you find a product like the Rab Mythic G that boasts superior performance, chances are good that it will be pricey — and at $525, it is. However, this is a high-performance, technical puffer designed for enthusiastic outdoor endeavors. For folks who get out and stay out quite often and depend on their gear for safety, the reliability and performance may be worth the price tag.
How it compares
If you feel like the Mythic G is overkill for your intended purposes but still need a warm puffer for dawn patrol, consider the Rab Mythic Alpine. It’s not quite as warm or as light, but it’s still a high-quality piece that will get the job done for most folks. Or if you need something even less burly, take a look at the Rab Microlight Down Jacket. The latter is less technical and less warm, but it’s a great option for everyday wear.
Outside of Rab, another great option is the Mont-Bell Mirage Parka. It has 900-fill-power down but opts for box construction, a type of baffling that uses fabric to create a square-shaped pocket for the down. It can be warmer since it isn’t squishing the loft on the sides in the same way that stitch-through construction does, but it also adds a lot of weight (and the Mirage Parka is roughly 4 to 5 ounces heavier than the Rab Mythic G).
Bottom line
After six months of constant use, I couldn’t be more pleased with the Rab Mythic G puffy. If you’re an active outdoor enthusiast who spends a lot of time in the high alpine, cold temperatures or snowy environments, I think the technical performance far outweighs the high price tag.
