by Randy Johnson
iReview Gear Lead Field Editor
Altitude Outdoors Pro Staff

Basic Description:

KUIU’s mountain hunting clothing focuses on lightweight functionality and in utilizing the finest, “cutting edge” high quality materials. Designed for extreme, hardcore hunters who choose to engage hunting and life at a high rate of speed, KUIU is constantly searching for clothing materials designed for dependability, high performance, packability, and durability in helping Mountain Hunters rachet up “their game.”
Recently, Nuyarn,® by The Merino Company enabled KUIU to reinvent their collection of merino wool base layers. Nuyarn is an entirely new way of making fabric. Traditional spun yarn twists fibers together for strength, which leaves ends poking out. The Merino Company’s Nuyarn takes the twist out, and instead lays fibers along the same orientation as the rest of the yarn, so fabrics feel less prickly, more comfortable as the fabric is then strengthened. Nuyarn’s lower-density fabrics mean a lighter weight garment that can out-perform a heavier one made of traditionally spun yarn. These properties make Nuyarn ideal for a wide array of ULTRA Merino products. With Nuyarn’s new approach they have “righted all the wrongs” of traditional merino fabrics while maintaining the natural benefits of wool.

Facts and Features:

In KUIU’s search for new, innovative ways to make their Merino Wool clothing line better their discovery of Nuyarn, by the Merino Company in New Zealand, has helped them fine tune their Merino base layers. The Merino Company takes their wool very serious and came up with a new, cutting edge method of making fabric. Where traditional ring spun yarn twisted the life out of yarn, Nuyarn does not. The superior performance of Nuyarn versus traditional ring spun yarn has been proven by independently performed tests by the IANZ accredited Textile Testing Labratory at AgResearch. Please see the test results below:

kuiu chart nuyarn

Utilizing Nuyarn technology solves the basic problems of traditional
Merino, such as the retention of moisture and strength issues as well as
extending the comfort while against your skin. With the use of Nuyarn®,
ULTRA Merino has no itch or prickly wool fibers. It has reduced the weight
of KUIU’s previous Merino Wool base layers, while increasing drying
speed, loftiness, durability, and resiliency. The result is a stronger, lighter,
more comfortable fabric that outperforms heavier traditional ring spun
garments. All of the inherent merino features, such as odor resistanance,
temperature regulating, moisture wicking, and natural anti-microbial have
remained unaltered. The ULTRA Merino line also has enhanced design
features that allow for improved fit and comfort.

KUIU’s ULTRA Merino 145 line features the ULTRA Merino 145 LS Crew-T, ULTRA Merino 145 Zip-T, ULTRA Merino 145 Zip-Off Bottom, ULTRA Merino 145 Beanie, and ULTRA Merino 145 Neck Gaiter. This 145 gm style is made of 90% Merino Wool and 10% Nylon. Also, at 17.5 microns, the ULTRA Merino line is to replace the previous Merino 185 line, making it cool enough for warmer weather hunts, or as insulation for colder hunts.

KUIU’s ULTRA Mernio 145 lightweight collection is an incredibly comfortable blend of wool and nylon providing a next to skin or layered option for the highly active hunter. Naturally anti-microbial, moisture wicking and thermo regulating, the 145 is an ideal choice for hunters needing a long term effective solution in a wide range of aerobic conditions and temperature

• Independently tested by the IANZ accredited Textile Testing Laboratory at AgResearch to prove superior performance.
• 90/10 Wool Nylon blend – 145 g/m2
• 8.0 ounces
• 17.5 Micron wool fibers
• Thermo-regulating
• ½ Zip for heat release and added ventilation
• Lightweight next to skin or layered
• No itch and incredibly comfortable
• Moisture-wicking and quick drying
• Anti-microbial and odor resistant
• Ultra breathable
• Inherently stretchy
• No spandex fibers
• Left chest zippered pocket

(compared to traditional ring spun yarn)
• Reduces weight and increases loft simultaneously
• 38.9% loftier
• 35% stretchier
• Dries 5 time faster
• 25% warmer
• 16% Stronger

• Adds strength and durability
• Resiliency – Returns to natural shape
• Faster drying

• Anatomical shaping for fit and comfort
• Side panels for comfort and breathability
• Zipper garage for added comfort
• Gusseted underarms
• Flat lock stitching

• Knitted micro eyelets for enhanced ventilation
• Expand and contract with movement
• Regulate airflow
Maximized breathability

randy kuiu

kuiu nuyarn1

kuiu nuyarn2


I’m one of those individuals who can’t place enough emphasis on the importance of lightweight, quality, warm clothing. I have a slow metabolism with a resting pulse rate as low as 50 with blood pressure dipping to 90. In other words, I get cold easily and with weight at a premium when backpack hunting I need lightweight clothing that is warm because I don’t want to have to wear a lot of heavy clothing that restricts my movement. On my list of hunting gear this type of clothing is worth every cent that I’m able to invest! Lightweight, warm hunting clothing has become a mandatory “change agent” on my list of quality hunting gear. This is why KUIU’s layering system and clothing line, including their new Ultra Merino Wool with Nuyarn plays such an important role in how I approach the hunting clothing that I use when spending a lot of time out on the mountain.
When KUIU announced the release of their Ultra Merino line, I did my research and was convinced that this collection would not only be lighter but stronger and warmer than other Merino Wool. After wearing the zip Merino 145 top and zip off bottoms last spring and summer I’m a believer. This unique blend of wool and nylon is very comfortable next to my skin, doesn’t itch, and amazingly doesn’t retain body odor. Wearing these items as base layers and then adding KUIU’s Superdown jacket with Quixdown has been a great combination for keeping warm and they are very light to pack. The zip off bottoms are designed so that I can easily remove them. I was skeptical at this design at first but have found it to be very efficient. The enhanced design features of KUIU’s Merino base layers have increased their comfort, fit and functionality

At a price range of $79.99 for the Merino 145 Zip T and Zip Bottoms, both are affordable and well worth the investment. Both come in Ash Brown, Brindle, Forest, Stone and the traditional Verde and Visa Camo colors

What They Could Do Better
Great products. The Nuyarn technology is a positive step forward for Merino Wool.
Thanks for reading my reviews everyone. Good luck and continue to “keep your boots” warm for your next adventure out on the mountain.

  • Functionality
  • Value
  • Ergonomics
  • Durability


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