Get Better Trail in your inbox.

Subscribe here.
MENU

REI Co-op Midweight Base Layer Review

Ashley McNeish (ski gear tester)
ByAshley McNeish
Aug 27, 2025
When you buy through our links, we may receive a commission.
Our Take:
4.4/5
Certified

The REI Co-op Midweight delivers solid value for those seeking an affordable, all-purpose synthetic base layer. It’s soft, stretchy, and more comfortable than many techy synthetics, with enough warmth for most winter activities and durability that far outpaces merino at this price. Breathability and odor resistance fall short of higher-end options, making it less than ideal for high-output pursuits. But for $55, it’s a reliable, versatile piece that punches above its weight in comfort and quality.

Warmth

Warmth

3/5
Breathability

Breathability

3.5/5
Durability

Durability

3.5/5
Comfort

Comfort

4/5
Odor Resistance

Odor Resistance

3/5
Sustainability

Sustainability

5/5

Fabric(s)

92% polyester, 8% spandex

Fabric weight

220 g/m²

Weight

9.7 oz.

Variations

Half-zip

Pros

Very affordable at just $55.
The midweight fabric feels substantial and holds up well to wear.
The generous length makes the top easy to tuck in.

Cons

Not as warm as merino base layers of a similar weight.
Those with sensitive skin might find the material to be slightly scratchy.
Simple design with no significant fabric tech or added bells and whistles.

For this season's top models, see our guide to the Best Base Layers.

With a 220-grams-per-square-meter (g/m²) polyester build, the REI Co-op Midweight sits squarely in the midweight category. On paper, it appears warmer than a base layer like the Arc’teryx Rho (190 g/m²), but in practice, it offered about as much insulation as the REI Co-op Merino 185, if not a little less. On a test day in the mid-20s with steady snow, it provided a solid foundation but didn’t stand out as particularly warm, and it certainly lacks that instant-insulation feel you get with merino. I wore it under a midweight waffle-knit quarter zip, a Patagonia Nano Puff, and the Patagonia Powder Town ski jacket, and the system kept me comfortable without overheating.

Synthetic fabrics like the REI Co-op Midweight’s polyester generally excel at breathability, but this piece isn’t the best option if airflow is your top priority. Its relatively thick fabric insulates more than ideal for high-output activities and dries slowly once saturated with sweat. Compared to high-performance synthetics like The North Face Summit Series Pro 120 or Patagonia Capilene Thermal Weight, which use lighter fabrics and raised grid patterns for ventilation, the Midweight feels basic. Even the merino-blend Smartwool Intraknit Thermal adds strategic mesh vents for better heat management. All told, the Midweight is serviceable for moderate activity but far from our first choice for breathability-focused performance.

The REI Co-op Midweight feels impressively durable and well-made for its price point. The 92% recycled polyester and 8% spandex blend has a substantial feel, and after multiple washes (air-dried afterward), it shows no signs of pilling or wear. It does lack the harder face of synthetics like the Arc’teryx Rho LT and The North Face Summit Series Pro 120, which I’d be far more likely to wear as standalone pieces while hiking or even climbing. But compared to merino base layers of a similar weight, the Midweight is far more resistant to tearing and abrasion. For $55, the durability-to-price ratio is excellent.

When I first tried on the REI Co-op Midweight, I was pleasantly surprised by how soft and comfortable it felt. Unlike many synthetics—such as The North Face's Summit Series Pro 120 or Outdoor Research's Echo—that have a plasticky, tech-forward feel, the Midweight feels more natural, somewhere between cotton and merino wool. I wouldn’t hesitate to wear it under a sweater to work—that’s how non-techy and wearable it feels.


The fabric’s 8% spandex adds plenty of stretch, making it easy to move in without restriction. The regular fit further boosts all-day comfort—close enough for layering but never tight. Thoughtful details like thumbholes (perfect for hiking without gloves), offset shoulder seams, and a well-placed neckline seal the deal. Unlike some base layers that creep too high under the chin or dip awkwardly in the back, the Midweight’s neckline hits just right.

Odor resistance has never been a strength of synthetic base layers, and the REI Co-op Midweight is no exception. While many modern synthetics use antimicrobial treatments to combat lingering odors, the Midweight sticks to a simple 92% polyester and 8% spandex build with no added protection. After just a few uses, it develops that classic “base layer smell” that washing only partially removes. At $55, it’s hard to fault it too much, but if odor control is essential, opt for merino or a treated synthetic alternative.

Select icon to view details:

Icon
Icon
Icon
Icon
Icon
Icon
Icon
Icon

Longevity

Choosing durable outdoor gear and keeping it in use for longer is one of the best ways to reduce environmental impact. Our proprietary longevity rating assesses factors like overall build quality, materials, fabric denier, component durability, and real-world performance. A green check indicates that we expect the product to be long-lasting relative to its peers, a yellow check mark indicates average longevity, and a red X indicates a product that may have a limited lifespan.

Tester: 5’4” 145 lb.; 36" chest; 30” waist

Size tested: Women’s medium

I usually wear a small for a snug fit and a medium for something more relaxed, and since I hadn’t tried REI tops before, I wasn’t sure what to expect. The medium ran true to size with a regular fit—not skin-tight but not overly loose either. Personally, I prefer a little extra room, so I was happy with the choice. The length is good for layering, and I appreciated the thumbholes, which keep the arms in place when I pull on my midlayer.

Helly Hansen Lifa Stripe ($45): An Iconic Budget Base Layer
The Helly Hansen Lifa Stripe is an iconic polypropylene base layer that has been a staple in the ski world for decades. It lacks the clean and classy vibes of the REI Midweight (the striped arms won’t pass in casual settings), and the polypropylene material feels more techy than the Midweight’s soft polyester. But it’ll save you $10 and definitely fits the part at the ski resort. To learn more, check out our Lifa Stripe review.


REI Co-op Merino 185 ($80): REI’s Midweight Merino
Merino offers several clear advantages over synthetics, including excellent warmth-to-weight performance and outstanding odor resistance, making it a favorite for multi-day use. Affordable merino is rare, and at $80, the REI Merino 185 is a decent deal. Compared to the REI Midweight synthetic, it delivers slightly more warmth in a lighter, thinner package. The trade-off? Durability takes a hit, and our tester found it noticeably scratchier than premium merino options. And neither are great choices for sweat-inducing activities. If you're looking for budget-friendly merino, we’d still recommend the Ridge Merino Aspect Midweight for its softer feel and added nylon for durability. For more, read our review of the Merino 185.

REI Co-op Midweight ($55)
Wrist of REI Co-op Midweight LS Base Layer
4.4/5

The Co-op’s Midweight is an affordable, no-frills base layer that’s built to last. But while it gets the job done for casual users, it’s not a standout for comfort, breathability, or warmth.

Fabric(s)
92% polyester, 8% spandex
Fabric weight
220 g/m²
Weight
9.7 oz.
Variations
Half-zip
Icon

Warmth

3/5
Icon

Breathability

3.5/5
Icon

Durability

3.5/5
Icon

Comfort

4/5
Icon

Odor Resistance

3/5
Icon

Sustainability

5/5
Helly Hansen Lifa Stripe ($50)
Layering overtop Helly Hansen Lifa Stripe LS Crew Base Layer
3.8/5

The Lifa Stripe is an iconic layer from Helly Hansen for just $50. It’s all function here: The polypro material feels somewhat plasticky and isn’t particularly cozy, but it moves sweat away from the skin and dries quickly. Unfortunately, the fit isn’t refined, and there’s no odor-resistant technology.

Fabric(s)
100% polypropylene
Fabric weight
Unavailable
Weight
5.3 oz.
Variations
None
Icon

Warmth

2/5
Icon

Breathability

4/5
Icon

Durability

4/5
Icon

Comfort

3/5
Icon

Odor Resistance

2/5
Icon

Sustainability

3.3/5
REI Co-op Merino 185 ($80)
Woman packing car in REI Co-op Merino 185 LS Base Layer Top
4/5

The Merino 185 is REI’s 100% merino base layer. The 185-gram weight is a nice middle ground between light and heavyweight alternatives. However, it’s not as soft as we’d prefer and won’t hold up to heavy use as well as merino-nylon blends.

Fabric(s)
100% merino wool
Fabric weight
185 g/m²
Weight
8.2 oz.
Variations
Half-zip
Icon

Warmth

3.5/5
Icon

Breathability

3/5
Icon

Durability

2/5
Icon

Comfort

3.5/5
Icon

Odor Resistance

5/5
Icon

Sustainability

5/5

Is the REI Midweight for You?

The REI Co-op Midweight is a smart choice for budget-conscious adventurers who want dependable warmth and synthetic durability at an approachable price. It strikes a comfortable middle ground—soft, stretchy, and comfortably suited for casual winter activities and layering under casual attire.


Go for it if you value affordability and need a no-frills base layer for skiing, hiking, or daily layering.


Skip it if you prioritize high-output breathability or advanced odor control—you’d likely be better off with merino or more technical synthetic alternatives.

enter the white room

Skiing Gear Guides

Ski Kit Mash Up

curated for you

Better Trail Ski Kits

Picking up skiing for the first time or looking for gear to match your specific style? We've got a kit for that. Check out our curated ski kits for every type of skier, from beginner or budget-oriented to expert freerider, backcountry, and more. All there's left for you to do is grab your ski pass (or skins) and hit the slopes.