Isobaa Merino 150 Women’s T-Shirt Review

Isobaa Merino Women's 150 t-shirt

Isobaa Merino Women’s 150 t-shirt

Last year I tested the Isobaa Merino 180 Women’s  long-sleeved baselayer, and was so satisfied with it that it became a wardrobe staple for me – on and off the trails. This year I was so fortunate that I also got to test its lighter short-sleeved cousin – the Isobaa Merino 150 women’s t-shirt. I received the t-shirt in December 2019 and have thus been testing it for quite some months now. I have used it for both outdoor and indoor activities as well as for everyday life, and can conclude that Isobaa Merino 150 t-shirt is suitable for:

  • Hiking
  • Mountaineering
  • Backpacking
  • Trekking
  • Travelling
  • Climbing
  • Everyday use


Like most of Isobaa apparel, the women’s t-shirt is made of 100 % superfine (i.e. 18.5 micron) Merino wool. As the name implies, the density of the fabric used for the Isobaa Merino 150 t-shirt is 150g/m2. This density is, as far as I know, the lightest density for 100 % Merino fabrics; Icebreaker and Formal Friday’s lightest shirts of this kind for example have densities of 175g/m2 and 156 g/m2 respectively. Lighter (but still durable) densities are only achieved by mixing either silk or synthetic fibers with the Merino wool. When the fabric is 100 % Merino like Isobaa’s, you, however, get all the qualities of the pure material like breathability, natural temperature-regulation, odor-resistance, softness, and wrinkle-resistance.

My only reservation with the fabric, and indeed with the entire t-shirt, is that it started piling after just a very few washes (following the instructions, using a special wool detergent). Piling is when fibers tend to come loose from a fabric surface and form small balls of fiber particles. People have different attitudes to piling on apparel, but I myself think that it makes the garment look cheaper and more tattered. I wonder if it could be due to the light density as we have not experienced any piling on the other Isobaa garments we have tested – which are all made of fabrics with higher densities. Another (insignificant) durability issue is that both the printed sheep head logo in the neck area and washing instructions printed on the inside of the shirt near the left side seam are peeling off. But being an experienced Merino wearer and carer I’m not likely to forget how the garment is supposed to be washed, and the cute-cool sheep head logo is anyway embroidered on the right sleeve – a detail that I absolutely adore on Isobaa’s tops.

Comfort, fit and sizing

As mentioned in our reviews of the Isobaa Merino women’s 180 shirt and men’s 200 hoodie, these base layers are rather long in the torso which may be an advantage or disadvantage depending on your height. I for instance measured the long-sleeved 180 shirt to be 5-8 cm (2’’-3’’) longer in the torso than other outdoor tops I own. The Isobaa Merino 150 t-shirt does not have that extra length, but is quite standard length. It does, however, still have that drop tail hem for additional coverage so you can raise your arms, reach, stretch and bend without having the shirt riding up in the back.

For additional comfort, the washing instructions have been printed on the inside of the shirt rather than on a potentially chafing washing tag, and also the name logo tag is stitched on the front hem where it shouldn’t chafe you – provided that you have the right size, of course! I went for a size M, like for the long-sleeved Isobaa base layer, and as it is seen on the images the fit is relaxed, but still following the female silhouette with a very slight narrowing at the waist rather than a completely straight up and down inseam.


In terms of functionality for hiking and other outdoor activities, the Isobaa Merino 150 t-shirt has quite a few well-considered features. The drop tail hem is one, but even for important for actual freedom of movement are the underarm gusset panels, which are also constructed so you don’t have any seams potentially chafing you in the sensitive armpit area. The seams surrounding these panels as well as the majority of the seams on the t-shirt are made with flatlock seams for extra comfort. The shoulder seams are also offset, i.e. slightly down, approximately in line with the collarbone in order to prevent potential chafing on top of your shoulders if carrying a (heavy) backpack. This is an increasingly important feature for me after we have started hiking with our baby and we both have to carry a backpack (Blaz carries her and I carry water, supplies and a sleeping bag for breaks). I wore this t-shirt on two of the hikes we did in Norway in June.

Washing and drying

The Isobaa t-shirt should be washed in cold water (30⁰ C or less, whether by hand or machine) and air-dried, preferably flat. You should avoid using so-called bio detergents (contain enzymes which can damage the wool fiber), fabric softener and bleach and tumble-drying the garment. The t-shirt is available in a range of stylish solid colors as well as striped versions; whichever you choose, you should wash it with similar colors.


The Isobaa Merino 150 women’s t-shirt is full of functional details which make it perfect for various outdoor activities like hiking, climbing, mountaineering etc. Due to the characteristic properties of Merino wool along with the light fabric, the t-shirt is suitable for all seasons, except perhaps the coldest of winters where you’ll want something long-sleeved and thicker. The only downside is the piling.

If you have any questions about this product, drop me a line in the comments below.

Isobaa Merino 150 Women's t-shirt: Sustainable packaging

Isobaa Merino 150 Women’s t-shirt: Sustainable packaging

Isobaa Merino 150 Women's t-shirt: From the side

Isobaa Merino 150 Women’s t-shirt: From the side

Isobaa Merino 150 Women's t-shirt: Embroidered sheep logo

Isobaa Merino 150 Women’s t-shirt: Embroidered sheep logo

Isobaa Merino 150 Women's t-shirt: Offset shoulder seam

Isobaa Merino 150 Women’s t-shirt: Offset shoulder seam

Isobaa Merino 150 Women's t-shirt: Name logo tag at bottom hem

Isobaa Merino 150 Women’s t-shirt: Name logo tag at bottom hem

Isobaa Merino 150 Women's t-shirt: Underarm gusset

Isobaa Merino 150 Women’s t-shirt: Underarm gusset

Isobaa Merino 150 Women's t-shirt: Printed washing instructions (slightly peeling)

Isobaa Merino 150 Women’s t-shirt: Printed washing instructions (slightly peeling)

Isobaa Merino 150 Women's t-shirt: From the back

Isobaa Merino 150 Women’s t-shirt: From the back



We field tested this product. The rating shows its overall performance.About Rating


  • All the benefits of light-weight 100% Merino wool
  • Underarm gussets for great freedom of movement
  • Droptail hem for extra coverage
  • Offset shoulder seams


  • Piling



Tested by: Laura P.
Review published:
Review updated:
Product: Isobaa Merino 150 Women’s T-Shirt
Final rating: 5 out of 5

How helpful was this post?

Click a star to rate it!

2 vote(s) so far. Average rating 5 out of 5.

Author Information

Laura P.

I loved to climb trees when I was a child – as an adult I use these skills for climbing and scrambling up mountain sides! I always wear a Merino base layer, sunscreen and my hair tousled.

Leave a Reply

Your email address will not be published. Required fields are marked *

2 comments on “Isobaa Merino 150 Women’s T-Shirt Review

I really liked your review on Isobaa Merino 150 Women’s T-Shirt, I just ordered one week back before reading your review. I am only starting out with Merino wool. Can you tell which brand in merino wool did you find prefer, if you can include long sleeve & short.


Hi Oonagh, I’m happy that you found the review useful. We have reviewed a lot of Merino base layers through the years, but I have to say that one of the (European) manufacturers which have impressed me the most with a good balance between quality and price is the Czech brand Lasting Merino, which we have reviewed a few base layers from. I also really liked the Merino-Silk blend t-shirt from Klattermusen. The best quality all-over, I think has been from Finnish brand Formal Friday, but their fit is “unisex” and thus pretty horrible for women. Hope this can help you on your Merino journey – otherwise write again 🙂

Best Hiking Gear Deals

Save big on hiking gear! See the latest deals.

Hiking Gear Deals