Our Verdict
Our Analysis and Test Results
A super comfortable and thick wool/synthetic blend fabric defines the Stio Basis PeakWool Midweight Half Zip, destined to keep the wearer warm despite cold weather. A high collar and thumb loops help to seal in heat, while the half-length zipper helps quickly dump out surplus heat. Quality is obvious anywhere you look on the PeakWool, from the flatlock seams used throughout to the comfortable panel shoulder design.
Likes
The varied synthetic/wool blend (56% Merino Wool, 23% Tencel, 12% Recycled Nylon, 7% Nylon, 2% Spandex) of the Stio Basis PeakWool Midweight Half Zip fabric is spun up to a heavy 280 g/ms weight, making it extremely comfortable to wear. The fabric blend that includes nylon for strength and a little elastane for stretch should keep its shape better than a 100% merino top throughout its life.
We enjoyed many of the details found throughout that enhance its comfort, like the burly half-zipper, which helps thermoregulate, and the high collar and thumb loops at the cuffs, which help lock in heat.
Layering ability is also top-notch. Piling additional layers on top is a sure way to craft a great winter layer system for cold weather, and the PeakWool Midweight is reasonably durable enough to be worn all by itself, with a look refined and finished enough to be appropriate for casual public outings.
Dislikes
Like many other heavier base layers, the dry time on the line for the Stio Basis PeakWool Midweight Half Zip isn't great; this top took longer than most to fully dry. Heavier fabric and its tight weave absorb more moisture, which then takes longer to naturally evaporate.
This also usually suggests that if you do get sweaty while wearing the PeakWool Midweight, it'll also take a while to get dry, and a wet base layer is just colder and more clammy than a drier one.
And despite its heavier weight, our workout tests didn't indicate that the Stio Basis PeakWool Midweight Half Zip punched above its weight class when it comes to warmth, only being slightly above average when compared to our entire lineup. What you do get for the weight is, instead, seemingly endless comfort and durability.
Coming in at 13.1 ounces for a size “large”, the Stio Basis could very well be too much base layer for some applications once the mercury starts to rise. Keep this base layer close at hand when the flakes start to fly, and the ropes for the new groomers start to drop.
Should you Buy the Stio Basis PeakWool Midweight Half Zip?
Heavier base layers are undoubtedly warm and comfy, and the Stio Basis PeakWool Midweight Half Zip is no exception. The PeakWool works best as a base layer in cold, wintry conditions. We would suggest it over a 100% merino base layer of a similar weight if you're worried about durability in the long run. This is a top-tier base layer with exceptional stitchwork and quality, ready to support you during cold-weather adventures on the tops of mountains or right next to the lodge's fireplace with your favorite book.
What Other Base Layers Should You Consider?
The Smartwool Classic All-Season Merino 1/4 Zip is a cold-weather all-star, made with 100% merino wool spun up to a 250 g/sm weight. Treated with care, it's hard to beat for colder activities. The Arc'teryx Rho LT Crew is a fully synthetic base layer that nips at the toes of wool options, but is far more durable, perfect for those hard on their gear. A more budget-friendly option is the Meriwool Merino 250 Long Sleeve, a good introduction to heavier merino wool base layers.
| Awards | |
|---|---|
| Price | $160 List Check Price at REI |
Overall Score ![]() |
|
| Star Rating | |
| Bottom Line | A heavier wool/synthetic blend base layer that packs a lot of durability along with comfort |
| Pros | Synthetic blend fabric more durable than 100% merino wool, tough half zipper for themo-regulation, high collar to lock in warmth, "sweatshirt-like"" comfort |
| Cons | Heavy fabric doesn't necessarily equate to being warmer, slow drying speed on the line, expensive |
| Rating Categories | Stio Basis PeakWool... |
| Warmth (25%) | |
| Breathability (20%) | |
| Comfort and Fit (20%) | |
| Durability (15%) | |
| Drying Speed (10%) | |
| Layering Ability (10%) | |
| Specifications | Stio Basis PeakWool... |
| Fabric Weight Class | Heavyweight |
| Material | 56% Merino Wool, 23% TENCEL™, 12% Recycled Nylon, 7% Nylon, 2% Spandex |
| Fit | Loose |
| Odor Control Fabric | Naturally odor resistant |
| Time to Air Dry | 65 min |
| Thumb Loops | Yes |
| Dryer Safe | Yes, tumble dry low |
| UPF Sun Protection | None listed |
| Seam Stitching | Flatlock seams |
| Shoulder Top Seams | No |
| Drop Tail Hem | No |
| Measured Weight (Size Large) | 13.1 oz |
| Measured Shirt Length (Size Large) | 26.0 in |
| Available Cuts | Crew, Half-Zip, Hoodie |









