What is GSM and Why Does it Matter?

How GSM Affects Fabric

Fabric Thickness

As mentioned, GSM relates to a fabric’s weight. This is often based on its thickness. The heavier the weight of the fabric, the thicker it’s likely to be. For example, a fabric with a GSM of 350+ is likely to be a bulky material, such as wool felt or twill. That being said, while GSM can suggest how thick fabric is, it won’t tell you the exact thickness. Certain fabrics may have the same GSM but not the same thickness, due to the density of their fibers. Due to the process of our Nuyarn Merino, our clothing provides the same warmth as traditionally higher GSM fabrics without the weight that comes with their normally denser fabrics.

Fabric Quality

While a high GSM may suggest a fabric is hard-wearing, it does not determine the quality of the fabric. The weight of the fabric is very much dependent on the fabric’s use. For example, a light summer dress will obviously require a lower GSM than a warm winter coat. GSM also affects how much a fabric drapes. Meaning something with more structure, for example, a suit will have a higher GSM than a floaty blouse.

The special way in-which Nuyran drafts merino fibers results in full use of the materials natural benefits, making it tougher, stretchier and longer lasting than traditional merino.

Fabric Warmth

In general, the heavier the fabric, the warmer it’ll be. Winter clothes such as twill coats or puffer jackets will have a higher GSM than cotton t-shirts. If you’re planning a trip to a cold climate, seek out clothes with a high GSM to help trap heat.  Due to the technical properties of our Nuyarn Merino, you do not need to go as heavy as you traditionally would have in order to achieve the desired warmth.

Choosing the right GSM

Choosing the right GSM for you depends on several factors, including the activity or sport you’re doing, the weather, and the type of clothing you’re after.

•  The activity – For a relaxed walk in a cool climate, a higher GSM may be recommended. However, for sports that might make you sweat a lot like climbing go for a lightweight fabric with a low GSM.
•  The weather – As mentioned, colder climates are generally suited to heavier fabrics with a higher GSM. This is because usually the denser the material, the warmer you are likely to be when skiing in a cold environment.
•  The type of clothing – Choosing the right GSM also depends on the type of clothing you’re after. For example, if choosing a pair of jeans you’d want a higher GSM, which suggests better quality for its purpose than lightweight denim.

Recommended GSM by Activity

As mentioned, the best GSM for you largely depends on the activity or sport you’re doing. Different GSMs are best for different sports to ensure maximum performance without overheating.

Walking & Hiking

The best GSM for walking or hiking depends on the climate and how physically difficult your walk is likely to be. If there’s a lot of steep climbs or hot weather, opt for something with a low GSM which will offer more breathability. If you’re walking a steady gradient in a cold climate, consider something thicker. In general, if in doubt a midweight fabric with a GSM of 150-350 is the best all-rounder.

Mountaineering

Mountaineering requires warmth without too much weight. Therefore, we’d recommend a GSM of around 200-250. If you’re still a little cold, consider layering with base layers, mid-layers, and outer layers for extra heat.

Skiing

Skiing requires a similar GSM to mountaineering due to the cold climate. You need to keep warm but also ensure agility. Therefore, we’d recommend anything from 100-250gm. Again, rely on layering to ensure you can regulate a comfortable temperature and keep out the elements.

Cycling

Cycling can be a strenuous sport resulting in a lot of sweat. Therefore, lightweight breathable fabrics are best. Stick to a GSM of 150 or less to ensure a smooth ride. Base layers are ideal for cycling as they are light but can also wick away moisture and keep your skin dry.

Running

Finally, running also requires a low GSM as your body temperature is likely to rise. Again, opt for breathable clothing of 150 GSM or less to ensure maximum performance.

If you have any more questions about GSM or would like to know more about our clothing - get in touch today.