Merino Wool Fabric Weight (GSM) Explained

January 12, 2023 4 min read

Merino Wool Fabric Weight (GSM) Explained

What does GSM mean as it relates to Merino Wool fabric weight?

GSM stands for Grams per Square Meter and is the standardized method of quantifying the weight of fabric, especially where it pertains to Merino Wool layers and/or other outdoor apparel, gear and goods.

What is Merino Wool GSM

Why is this important? Well, there are a number of reasons one might want to know the weight of a garment, from perceived-to-actual warmth and thermoregulation generated by said Merino Wool layer, all the way to literally counting weight for extended and demanding trips into the backcountry (these folks are sometimes referred to as “pound counters,” people who very much consider the individual weight of every wool layer, piece of gear, and snack they plan to haul into the wild).

However, if you’re someone who just wants to score a few Merino Wool base layers for an upcoming trip or round-year use and you’ve never considered fabric weight before, interpreting gsm can, at times, be a little daunting.

Lightweight Merino Wool base layers (150-200 gsm)

Summer Weight Merino Wool Layers

Here at Duckworth, we consider just about anything under 200 GSM to be a lightweight wool layer. In our Montana Merino shop, those wool layer families include the following:

  • Vapor (150 gsm) - Our lightest Merino Wool layer line, Vapor is one of the most versatile in our entire offering. Perfectly adequate as a wool base layer for cold weather pursuits, such as skiing or ice climbing, Vapor is mostly championed for summer and warm weather wool layering. Why? Thanks to a proprietary blend of three textiles, starting with a foundation of our Merino Wool, Vapor is excellent at keeping the body cool and thermoregulated, while quickly wicking sweat away from the body.
  • Maverick (160 gsm) - Our 100% Merino Wool base layer line, Maverick, is also a lightweight wool layer - coming in at an ultra-light 160 gsm. Merino Wool is prized for it’s softness, thermoregulation, odor-free and durable characteristics, all of which can be found in Maverick. Thanks to that classic 100% Merino Wool base layer profile, Maverick makes for a great wool layer for camping all the way to an outstanding base layer in the coldest of winter conditions.
  • Polaris (175 gsm) - Polaris is among the most unique fabrics in our shop, thanks to a proprietary “waffle-knit” construction. What’s a waffle knit, and why does it matter? Well, those miniature depressions formed by the waffle actually act as mini air-trapping devices, storing either cold or warm air the in the Merino Wool base layer itself. Plus, this line makes for an excellent warmth generating wool layer, but is very breathable should you ever need to layer down and let in some cold air (i.e. the perfect Merino Wool base layer for backcountry skiing).

Midweight Merino Wool layers (200-300 gsm)

Mid Weight Merino Wool Layers

Next, we move on to our midweight Merino Wool layers and base layers, which live between 200-300 gsm.

  • Maverick Peak (220 gsm) - Much like its lightweight twin, Maverick, our Maverick Peak line is defined by a robust 100% Merino Wool layering composition. And just like with Maverick, that 100% Merino Wool base layer profile makes for an excellent durable thermoregulator - only with Maverick Peak, you’re looking at some 60 more gsm, perfect for those especially cold winter days that need a thicker and warmer Merino Wool layer to beat the elements.
  • Comet (275 gsm) - If you're looking for a Merino Wool layer ready to stand up to the coldest winter days, Comet is your answer. Duckworth's proprietary Comet fabric combines a 100% Montana-grown Merino Wool outer layer with a polyester inner layer. The polyester wicks sweat and moisture right off your skin and into the wool layer, where it evaporates (while providing some bonus warmth, considering Merino Wool actually grows warmer - on an atomic level - when introduced to water and water vapor).

Heavyweight Merino Wool layers

100 Percent Merino Wool Button Downs

Finally, we move on to our heaviest Merino Wool fabrics, our Powder Merino Wool fleece line and our 100% Merino Wool button-down shirts: Sawtooth and Snowcrest. 

  • Powder (300 gsm) - Powder remains a top seller, year after year. Why? This ultra-soft and cozy Merino Wool fleece line is a cold-weather beast, trapping tons of hot air against the body while providing a uniquely rugged style for a Merino Wool sweater. Incredibly durable and thermoregulating, we recommend having at least one of our Powder Merino Wool fleece items in your wool layer collection.
  • Sawtooth (370 gsm) and Snowcrest (710 gsm) - These 100% Merino wool button-down shirts aren’t your typical layer, as they were designed to be worn as a chore shirt or for daily casual wear. Still, our sheep ranchers wear these all winter long over their other Duckworth Merino Wool layers, blocking out snow, wind, cold and water with ease - especially in the case of the Snowcrest Shirt, coming in at a whopping 710 gsm.

How To Layer Merino Wool Clothing with GSM Info

Think of it like an inverted pyramid - toss on the lightest, thinnest Merino Wool layers first (by way of gsm), before tossing some heavier gsm Merino Wool layers over them. Layering Merino Wool clothing really boils down to a matter of preference and anticipated weather conditions.