Review: Mammut Tree Wool FL Merino Long Sleeve Shirt

Natural fabrics and fibers are where it’s at. I love the sustainability and the feel of Merino Wool shirts and choose to wear them as often as I can. The Mammut Tree Wool FL long sleeve has been my go-to since arriving for review. I not only wear it trail running and hiking, but almost every day — so much that my family is now wondering if I have any other shirts to wear. My personal wardrobe choices aside, Mammut has a winner and it’s not only comfortable, but it’s also well-priced.

Mammut Tree Wool FL Long Sleeve Shirt Features:

• Merino wool and Lyocell blend (50/50)
• RWS-certified wool to protect animal welfare
• Fast-drying blend
• Underarm gusset for freedom-of-movement
• Relaxed cut
• MSRP: $79

Tree Wool? Indeed.

Mammut is onto something. Blending wood pulp Lyocell and natural Merino wool gives you what they call “Tree Wool.” I didn’t get the pun at first, but now I do and the combination is outstanding — maybe even the best Merino blended fabric I’ve tested to date. For those familiar with Merino wool, you can skip to the next paragraph, but if you’re new to this wonder-fabric, read on. 100% Merino wool is no bueno. Well, I mean it’s great for sheep, but not for humans. Merino shirts are blended with other fibers to add moisture wicking properties and to add durability or stretch. The combination of yarns is what makes an Ibex, Smartwool or Mammut Merino shirt what it is.

Upon arrival, I was impressed by the softness of the Merino/Lyocell fabric. It feels ultra-comfortable next to my skin. And, it drapes well too. It simply fits like an old, worn-in shirt. Mammut gave this shirt added length for proper coverage during physical activity and lounging around. And, the “relaxed” fit is just right. I opted for the size medium, and it fits perfectly.  Any bigger and it would feel gangly… any smaller and it wouldn’t be suitable for anything other than athletic use. The fabric is lightweight and very porous and looks great in the Marine Melange color.

My primary testing thus far has been trail running. I’ve worn it underneath the PEARL iZUMi Summit Wind Jacket on colder mornings in the upper 30’s and low 40’s. Then, I’ve worn it with a vest in the mid 40’s and alone when it’s been warmer than that. No matter the layering, I’ve been treated with consistent moisture management and comfort. Mid-run the fabric does manage to capture a bit of moisture, but it never gets pulled out of shape. There’s enough structure to the weave that it maintains itself well.

After running, I’m always surprised how fast it dries out. I’m not kidding when I say it immediately disperses the moisture and dries out faster than I can even take time to notice. A few minutes later and it’s dry. Even more astounding is how well it manages moisture. I can honestly run in the Mammut Tree Wool FL, then wear it all day and run in it again the next day and wear it all day again — all without it capturing body odor. As a multi-use workout layer or a travel shirt, this is the one to wear.

The fit is spot-on and comfort is unquestionably aided by the gusseted underarms. This allows fluid motion while running or doing other activities. While some shirts may get restrictive, this one just moves with me like a second skin.

As far as care goes, I’m doing my best to lay it flat to dry, but in a house of 5 people, that doesn’t always happen. If it does get dried, it stretches back out after a run to the proper size. When I do lay it flat, it maintains the same fit as the first day. Do your best not to dry it, but if you do, just make sure and lay it flat to dry the next time for the best experience.

Fit: I’m 5’11” and 178 lbs. and I’m wearing the size Medium Tree Wool SL. 

Buy Now: Visit Mammut.com