Reviews You Can Rely On

REI Co-op Merino Midweight Review

A super comfortable 100% merino wool midweight base layer that is warm enough for winter ventures but light enough to carry you through Spring and Fall outings
gearlab tested logo
rei co-op merino midweight base layer review
Credit: REI
Price:  $80 List
  • 1
  • 2
  • 3
  • 4
  • 5
Manufacturer:   REI Co-op
By Roland Mott ⋅ Review Editor  ⋅  Nov 15, 2019
  • Warmth - 25% 7.0
  • Breathability - 20% 6.0
  • Comfort and Fit - 20% 6.0
  • Drying Speed - 10% 6.0
  • Durability - 15% 6.0
  • Layering Ability - 10% 6.0

Our Verdict

The tough part of OutdoorGearLab reviews is that we choose only the best to test and then critique them obsessively picking them apart from every possible angle. Sometimes this can make a product that performs well seem like it's bottom-of-the-barrel in comparison to the best of the best. This is the REI Co-op Merino Top. A fantastic top that performs well, is comfortable, breathes and does a good job wicking sweat away from your skin. It is the lowest scoring Merino wool layer. That means it is a great all-around top but didn't stand out in any specific category in comparison to the other tops. Overall this is a layer that gets the job done, and you'll be happy with it, but if you want a base layer that performs extraordinarily in a specific category, we've got those too. But for the price, it's tough to find a solid Merino wool top that's less expensive than this REI model. This top does great for any outdoor venture in mild to cold temperatures. Resort skiing, hiking, fishing, or hiking. It doesn't perform at the highest standards but is adequate across the board.
Super comfortable
Odor resistant
Fun colors
Wicks well
Not durable
Loose fit thru torso
Loses shape after consistent washing/drying
New Colors Available

Since our testing period, REI gave this base layer some new color choices. One is pictured above.

September 2019

Our Analysis and Test Results

REI's Merino wool base layer enters the field as a contender as a comfortable and versatile midweight base layer to keep you warm and dry through the ski, hiking, and fishing seasons. A soft and cozy feel against the skin with a good fit, sensible design, and fun color combos allow this REI base layer to enter the big leagues. Although this layer isn't an all-star yet it has least entered the ring.

Performance Comparison

rei co-op merino midweight base layer review - with a loose fit through the torso and tight fit through the arms...
With a loose fit through the torso and tight fit through the arms, this could use some fine-tuning. We love the color and the casual fit makes it easy to throw it over another layer.
Credit: Roland Mott


This top offers a pretty standard warmth rating when stood against other Merino tops of comparable weight. Warm enough to keep you comfortable through resort season, hiking thru the snow and fall leaves, and backpacking in the crisp temps of early spring. It does well as a stand-alone layer, wind doesn't cut through it like more breathable options, and ups the toasty factor when layered.


This top scored average in almost every category, including breathability. That means it is efficient and better than the majority of base layers out there but not the most breathable top available. This is going to do a great job breathing in almost every situation you put it in except the most extreme demanding examples of extreme cold mixed with high-intensity output.

For the everyday user and outdoor enthusiast, it breathes well, wicks sweat and dries fairly quickly but is not at the top of its class.

rei co-op merino midweight base layer review - all parties involved breathing hard through technical terrain. the...
All parties involved breathing hard through technical terrain. The breathability of this merino was sufficient enough to keep us dry when working up a sweat, but didn't stand out above the crowd.
Credit: Roland Mott

Comfort and Fit

The Merino wool is soft next to skin, and the itch is minimal and reduces with washings but still tended to be a little itchier than other Merino layers. The printed tag sits smoothly against your neck. This layer sits baggy through the torso. Excess fabric under the arms and loose hem that feels a bit sloppy. It fits more like a long sleeve cotton t-shirt. This top lacks the thoughtful design and purposeful fit of other layers in this review.

We might consider sizing down for a traditional, snug base layer fit. Offset shoulder seams are great for carrying a backpack. Slightly longer drop-tail hem helps keep it from coming untucked or staying under a backpack hip belt. The drop-tail hem is also key when rolling over onto your side in your sleeping bag and exposing the small of your back to the cold. Minor underarm gusset reduces pull on your shoulders when lifting arms above your head but isn't as good as other brands' gusseted underarms. Tapered sleeves hug arms well and are snug against the wrist. Looks good enough that it can be comfortably worn as a stand-alone layer around town.

rei co-op merino midweight base layer review - the only top without flatlock seams although that didn't seem to...
The only top without flatlock seams although that didn't seem to make a big difference. Tight arms and a loose body made for an odd fit.
Credit: Roland Mott

Overall, the fit is okay. The body is loose and a bit awkwardly baggy while the arms are tight and tapered making it an odd combo. It shrunk and changed shape after washing and drying.

rei co-op merino midweight base layer review - a good visual of the tight arms and loose torso. if you're not...
A good visual of the tight arms and loose torso. If you're not ripped like this dude the bagginess in the torso is more evident.
Credit: Roland Mott

Drying Speed

This top came in the bottom half of the bunch in the dry speed test. It was the second slowest Merino layer to dry, and took 10 minutes longer than other tops of similar weight.

Merino layers are known for being heavy when wet and slow to dry, although all the Merino layers dried faster than the majority of synthetic tops that we tested.

rei co-op merino midweight base layer review - offset shoulder seams and an underarm gusset were nice but overall...
Offset shoulder seams and an underarm gusset were nice but overall fit could use some fine-tuning.
Credit: Roland Mott


Merino is more durable than it used to be but still not a quality that it's known for. In our abrasion test, we wore a hole through the fabric.

This top was one of the only layers to shrink/change shape noticeably after washing and drying. Not the most durable but not the least, again this top finds itself falling in the middle of the pack.

rei co-op merino midweight base layer review - the rei co-op merino midweight showing its war wound after our...
The REI Co-op Merino Midweight showing its war wound after our abrasion test in the lab. This was the only 100% merino layer that developed a hole from our abrasion test.
Credit: Roland Mott

Layering Ability

This layer has the smoothest feeling face fabric of all the Merino tops we tested which helps with layering. The smoothness allows it to not stick when putting a tighter fleece mid-layer over top of it.

However, the bagginess through the torso makes it feel a bit bulky and bunched up under a tight mid-layer. The looser fit and baggy hem allow it to fit naturally over a t-shirt but the tight sleeves don't work over another long sleeve.

rei co-op merino midweight base layer review - racked up and ready to roll. turns out, this layer was not our...
Racked up and ready to roll. Turns out, this layer was not our preferred top for dragging up rough rock routes but did a pretty good job at breathing.
Credit: Roland Mott


This top is the cheapest 100% Merino wool layer but is also the lowest scoring Merino wool layer so we'd say the value is appropriate to the performance of the top.

rei co-op merino midweight base layer review - as the cheapest merino layer we tested, we found it was also the...
As the cheapest merino layer we tested, we found it was also the least quality crafted and least durable.
Credit: Roland Mott


Not a home run hitter in any category but a consistent performer for the price point. It is soft, comfortable, warm, breathable, versatile, and looks good around town or apres ski. All in all, it doesn't receive our highest marks but does get an accepting head nod, letting it know that it's doing a good job and has the potential to become something great someday. It's good, but not great like most breakfast diners.

Roland Mott