Ultralight Jacket Packs Alpaca Fiber Insulation: PAKA Mayu Review

Whenever I pack for a fall backpacking or climbing trip, I always go back and forth about whether I should bring one item: a puffy jacket. Carrying one takes up space and adds some (arguably negligible) weight. During shoulder seasons, I often wonder if it’s really worth bothering.

After testing the PAKA Mayu Ultralight jacket, however, my internal debate over packing a puffy might be resolved. The comfort and warmth of the Mayu, plus its ultra-packability, has earned it a regular spot in my pack. 

I wore the Mayu jacket on several climbing, hiking, and camping trips in Kentucky, Illinois, and Missouri in October and November. The temps ranged from the 30s to the 50s.

It’s easy for a jacket to keep you warm while you’re on the move. But I find that the true test of a jacket’s warmth comes when belaying, an extremely stationary activity. With the Mayu, even on cold mornings in shaded crags at Red River Gorge, I stayed comfortable as I belayed for as much as an hour at a time.

In short: The PAKA Mayu Ultralight Jacket ($250) is a versatile, light layer with a comfortable fit and easy packability. It’s great for hiking, climbing, traveling, and general day-to-day use. The insulation is a blend of synthetic fill and naturally sourced alpaca fiber, which is odor-resistant. At just 8.8 ounces, this jacket competes with ultralight insulated jackets from much larger brands. If PAKA adds a hood and tweaks the zippers, the brand could have a five-star jacket on its hands.

Compare the PAKA Mayu to jackets in GearJunkie’s guide to the Best Down Jackets and the Best Insulated Jackets.

PAKA Mayu Ultralight Jacket Review

The insulation of the Mayu eschews the typical down filling of most jackets for PAKA’s signature material, PAKAFILL. The insulation is 50% alpaca fiber, 35% recycled polyester, and 15% polyester. We’ve covered PAKAFILL in GearJunkie’s previous review of the Apu Parka.

The women’s Mayu weighs 8.8 ounces, and the men’s is 9.2 ounces. The natural insulation provides benefits that traditional down and synthetic insulation won’t, and is fully traceable to its source. Available in sizes S to XXL for men and XS to XXL for women, the Mayu also comes in an Ultralight Vest version.

Fit

As a female climber with broad shoulders and a narrower waist, I often struggle with finding jackets that fit well. Often, even when I size up from my normal medium to a large, jackets are still cut too tight in the shoulders and restrict my freedom of movement.

I’m tired of women’s jackets that fit like a second skin, and the Mayu was a great change of pace. I tested a large and had ample room, which made it easy to layer with the Mayu. When it got chilly at night (below 40), I added a light fleece beneath the Mayu and felt quite comfortable.

Before getting on the wall, I did warm-up exercises — pull-ups and stretches — without feeling any constraints from the jacket. While there was extra space in the waist and chest area as a result of me sizing up, it wasn’t overly baggy or billowy. It certainly didn’t interfere with keeping me warm.

Durability

In my attempts to put this jacket through the wringer, I was not careful with it. I scraped against rocks, shoved it in my pack, tossed it on bushes, and at one point, even let my dog use it as a bed. After careful inspection, I noticed no loose threads, holes, or other damage, except in one area.

I managed to break off a zipper pull (more about this below) on one of the side pockets in the first week of wearing this jacket.

Packability & Storage

You can store the Mayu by stuffing it into the internal zippered chest pocket. I appreciated how easy this was. Sometimes, storing packable jackets means fighting to get the zipper closed. The pocket was spacious and plenty large enough to stuff, zip, and go easily. 

When packed up, the jacket measures just 9 x 8 inches. It easily compresses, and I could shove it in the small empty spaces between climbing gear in my bag. It would make for a decent travel/camping pillow if you needed one on the fly.

I loved how large the main external pockets on the Mayu were. While scrambling around looking for climbs at The Red, I wanted to have my hands free, but also wanted to bring along the guidebook.

To my surprise, the hefty tome fit inside the pocket (and it zipped). You can easily fit all your essentials — beanie, gloves, phone, wallet — in these pockets.

Warmth & Weather Protection

Not only is the Mayu wind- and water-resistant, but PAKA claims that alpaca wool naturally stays warmer when wet than traditional down does. I wore the Mayu in drizzling conditions while bouldering, and found that it held up quite well. After about an hour of constant drizzling, I noticed the outside felt quite damp, but I still felt warm and didn’t notice any moisture inside.

One of my favorite climbing areas in Illinois has a stark divide. One side is sunny and warm, while the other never gets a lick of sun. The dark side can be quite chilly and windy. While I belayed in a dark corner, I was glad I had the Mayu with me.

Other Features

Yet another added bonus of alpaca wool, according to PAKA, is that it’s naturally anti-bacterial and odor-resistant. While I didn’t really sweat in the jacket, after a week straight of wear (which involved unzipping it and tossing it in the dirt right before I climbed, as well as sitting around campfires), I would feel comfortable wearing the jacket to an office or event without doing laundry.

As someone with sensitive skin, I’m unable to wear sheep’s wool against my skin. I was concerned I might be similarly sensitive to alpaca fiber. However, the recycled nylon lining provided enough of a barrier that I never found out.

Sustainability

As more and more consumers factor sustainability into their purchasing decisions, brands like PAKA are prioritizing eco-friendly practices. The Mayu is made with recycled nylon and polyester. The alpaca fibers in its PAKAFILL are traceable all the way down to specific farms in the Andes. Like the rest of PAKA’s products, the jacket is Bluesign-certified.

According to PAKA, choosing alpaca wool over down is also a better choice when it comes to animal welfare. This fabric comes from free-roaming alpacas (which need regular shearing to stay healthy), rather than birds that have been killed for their feathers.

PAKA Mayu vs. Competitors

Looking at the Mayu, the immediate competitor that comes to mind is Patagonia’s Nano Puff. I’ve had one of these iconic jackets for years, and feel safe saying that the Mayu can compete with the Nano Puff, and might even have a slight edge. While the Mayu is more expensive ($250 versus $230), it is over 2 ounces lighter than the Nano Puff (8.8 ounces versus 10.9 ounces). 

I also find the fit of Patagonia’s women’s jackets too slim, and I appreciate the roominess of the Mayu. In fact, compared to every other jacket on GearJunkie’s guide to the Best Down Jackets, the Mayu would be tied with the Mountain Hardwear Ghost Whisperer ($380) for the lightest jacket on the list.

Drawbacks

While function always trumps aesthetics when it comes to outdoor gear, I do think PAKA could improve the color choices. Both men’s and women’s versions of the Mayu come in only burgundy, black, and fossil (which I tested). 

I thought the fossil color was very blah and underwhelming. Not only is beige a very humdrum color, but it is also light enough to show every speck of dirt. In the future, a broader array of poppier colors could add some fun to the design of the jacket. 

It’s also worth noting that the Mayu doesn’t have a hooded option (yet). While not a dealbreaker, it would be nice if PAKA came out with a hooded Mayu for even more warmth.

Finally, the zippers. The main zipper on the jacket has a large pull tab that’s easy to manipulate, but I didn’t like the zipper pulls on the two side pockets. They’re just two small pieces of cord, joined together with a smooth plastic coating. The small dongle is difficult to grasp with gloved hands, and its plastic coating is slippery. I managed to snap off one of the side pocket zipper pulls within the first few days of having the jacket.

PAKA Mayu Ultralight Jacket: Conclusions

If you’re looking to add a travel-friendly, lightweight layer to your quiver, the Mayu is an excellent choice. The insulation is lightweight, warm, and weather- and odor-resistant. With the exception of the zippers on the pockets, PAKA has created a durable and versatile product.

The brand’s first ultralight insulated jacket can compete with some of the biggest names out there. That’s impressive for a small company.

On top of all of that, the naturally sourced and traceable insulation is eco-friendly and sustainable. The nylon components of this jacket are all also made with recycled materials. PAKA is making high-quality gear that puts the earth first, and there’s a lot to be said for that. The PAKA Mayu’s permanent place in my hiking and climbing pack has been well earned. This lightweight little puffy packs a punch.