Smartwool MerinoMax Half Zip


Manufacturer Description

This densely woven Ponte knit jacket offers maximum warmth with minimal bulk, keeping you warm even on the coldest days.


  • Main Fabric – 97% Merino Wool, 3% Elastane
  • Pocket Bag -100% Polyester
  • Semi-Form Fit
  • MerinoMax Double Jersey knit
  • 34cm (13 in) zipper with semi-locking logo slider
  • Secure zip chest pocket with Durawelt finish
  • logo zipper extension and Durawelt grommet for media cord routing
  • Low-profile in-seam thumbholes at cuffs
  • Flatlock seam construction eliminates chafing
  • Heat Transfer logo at left sleeve cuff
  • Tested size Medium
  • Weight – 379 g (13.4 oz)
    • Pit to Pit – 54.3 mm (21.4 in)
    • Center Back – 70.3 mm (27.7 in)
    • Sleeve Length – 88.6 mm (34.9 in)
  • Retail – $170

YMMV Review

If you have been following the site for some time now, then you know that I am a fan of wool. There are three big brands in the outdoor space when it comes to wool. Smartwool is one of those brands. They really came to fame with their socks but over the last couple of years have been also making some high-quality apparel piece. I was able to work with them to get a piece of their new collection to review. Smartwool revamped some of their fabrics for the fall 2012 collection, and the MerinoMax is one of those pieces. Thank you to Smartwool for sending me this top to review.

Front View – Click to See Larger


I tested the MerinoMax in a wide variety of environments. It is a midlayer, so I used it as such. For my primary warmth when summer camping and under a shell on some cold-weather hiking trips in late spring. I also wore it around town as it is comfortable. I tried to test it both when active and not.

Design ★★★☆☆

Appearance (20%) ★★★☆☆

Construction (30%) ★★★½☆

Features (10%) ★★½☆☆

Pockets (15%) ★★★☆☆

Sustainability (10%) ★★★★☆

Weight (15%) ★★½☆☆

The MerinoMax Half Zip is one of the several tops made of a new knit made by Smartwool. They use the MerinoMax jersey knit in a full zip and half zip as well as in a couple of other pieces. I tested the Half Zip. MerinoMax is a knit of 97% wool and 3% elastane. Smartwool gets their Merino Wool from New Zealand where the top wool is sourced. The farms in which Smartwool works with are Zque certified so you can trust the not only the quality of the wool but also the treatment of the sheep on these farms. If you would like to know more about Zque certification, click on the link below.

Wool has a lot of properties that make it great for outdoor activities. Among them are warmth when wet and being stink free. I have written an article on wool and the performance benefits of the fiber. Check out the article if you want to know more.

MerinoMax is a double knit jersey for extra thickness and therefore, extra warmth. It has been designed to be a midlayer but is comfortable enough to be worn next to the skin as well. All the seams have been flatlock stitched for comfort and to help eliminate chafing. The top has one left chest pocket with a polyester mesh pocket bag. This pocket has an audio port so you can run just headphone wires up the inside of top. For venting there is a half zip front to help you regulate temperature. The MerinoMax Half Zip has a medium-length collar to provide some extra warmth compared to a crew neck top. At the wrist cuffs they have been designed with a longer length on the back of the hand to provide slightly more coverage for warmth. There is also a thumb hole for longing the arms down and covering the hands more.

Back View – Click to See Larger

The top is fairly basic by design, relying on the properties of the wool to set it apart. I tested the mahogany color way which is what I would call maroon. The chest zipper has a white contrasting zipper which looks sharp on the mahogany. Smartwool is a company that wants to affect a positive change in the world. They are all about their values and believe in capitalism with a conscience. They obviously use wool as their primary fabric, which is sustainable and renewable. The only knock against them would be that their garments are knit overseas in Vietnam. Other than that Smartwool does a lot in the community and to support other organizations that are doing good. Smartwool is one of those brands that I like to support.

Pocket from the Inside – Click to See Larger

Fit ★★★½☆

Arm Length (15%) ★★★½☆

Comfort (30%) ★★★★☆

Cuff (15%) ★★★☆☆

Ease of Movement (20%) ★★★★☆

Torso Sizing (20%) ★★★☆☆

I tested the size medium MerinoMax Half Zip. I am between the small and medium in size. Since the top is made to be mainly a midlayer it does have a semi-form fit which means it is made to fit close to the body but not tight. For me since it was between sizes, the medium fit a bit looser. The torso has a length similar to a sweatshirt and hits me just below the waist. The arms have a similar fit as the torso with a little extra room. The length of the sleeves is good, and they feel if anything, on the longer side. I like the shape of the wrist cuffs but they are a little large. I like how the thumb loops are low profile, and you would not even know they are there. The thumb loops do work as expected but are not as comfortable as ones that are more contoured. The half zip has a fabric flap to keep it comfortable against the skin. The neck comes up to just below the skin and is snug but not tight. Some tops have a tendency to be too tight in the neck, but this one is just right.

Flat Locked Seams – Click to See Larger

The Merino Max knit is very comfortable against the skin. It is a tight-knit fabric which is soft to the touch. Between the fabric and flat locked seams, the half zip has been comfortable every time I wore it. The MerinoMax Half Zip is made with raglan sleeves to improve mobility with the arms. The fabric mix also helps as the 3% elastane gives the top an excellent stretch. This elastane also helps the top maintain its shape. If I was to do this top again I think I would go for a small as I like a tighter fit, but I do think it runs true to size so buy accordingly.

Performance ★★★½☆

Breathability (20%) ★★★★☆

Durability (20%) ★★★½☆

Ease of Care (15%) ★★★★☆

Versatility (15%) ★★★☆☆

Warmth (30%) ★★★½☆

The MerinoMax Half Zip is a warm midlayer. It is a double knit jersey and does a good job, especially on top of another wool layer. At 13.4 ounces, the top is a bit heavy when comparing warmth to weight when compared to a down jacket. It is, however, very similar to a fleece but much more sustainable. The top breathes really well as the tight knit lets air exchange. The wool also has been very durable. When I was camping I wore the top almost the whole time even when playing with kids and dogs and the top held up to everything, it still looks like new. As most Smartwool tops the MerinoMax Half Zip is easy to take care of. Most wool tops are now able to be machine washed but still have to be air dried. Not Smartwool’s, this top can be machine washed and dried. Still make sure you follow the directions.

Thumbloops – Click to See Larger

The MerinoMax Half Zip is a versatile top that can be used whenever you need some extra warmth. It can also be used as a baselayer, but for me it would be a little loose as a base in this size. I was not as much of a fan the thumb loops. While they are functional, they have been designed to be less noticed. This design definitely works as you really do not notice them when wearing the top. However, it is by this design that makes them not as comfortable as they could be. The chest pocket works well, and I really liked having an audio out. The pocket is a good size for a smart phone, and I had mine in there often.

Pocket Zipper – Click to See Larger

Overall ★★★½☆

Overall, the MerinoMax Half Zip is a solid top. It is not the flashiest top, but it is effective. The MerinoMax is warm, durable, and easy to care for. This is the best part of the top aside from it sustainability. Merino wool is an excellent fabric to use as it has some great benefits to it. It is warm even when wet, it is anti stink, and durable. The one drawback to this top is that it is not as warm for weight as other options out there. If you have not tried wool yet, then you should give it a look. The top is soft, comfortable, and not like old-time wool sweaters. The Smartwool MerinoMax Half Zip retails for $170. It is another wool top that just performs. As always, your mileage may vary.

Pros [field name=iFrame]

  • Excellent mobility with wool/elastane mix
  • Audio port in chest pocket
  • Easy care
  • Versatile, baselayer or midlayer
  • Comfortable, flat locked seams


  • Thumb loop was a little bulky feeling
  • Higher weight to warmth ratio

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About the Author

I am an avid runner, cyclist, swimmer, hiker, climber, skier and many other activities that would make this list too long. I started Your Mileage May Vary Reviews in Early 2011 to combine two of my passions: sports and gear.

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