When it comes to choosing the best clothing for your little ones, merino wool is a standout option. This magical fabric isn’t just cozy—it’s breathable, temperature-regulating, and durable, making it perfect for active kids year-round.

This article in our series Guide to Merino for Kids is all about different types of merino fabrics and how they are used. One key factor to consider when shopping for merino wool clothing is the type of fabric and the GSM (Grams per Square Meter) of the fabric, which tells you the fabric’s weight and how it will perform across different weather conditions. Let’s explore merino wool’s different GSM categories and fabric types to help you find the perfect balance of warmth, comfort, and durability for your child’s wardrobe.

What is GSM?

GSM, or Grams per Square Meter is simply a measure of how heavy the fabric is, and it plays a big role in how the garment performs in different weather conditions. Merino wool is famous for its ability to keep you warm when it's cold and cool when it's hot, but choosing the right GSM will help you find the perfect balance for your needs. Whether you’re after a lightweight summer layer or a cozy winter piece, this guide will walk you through the different GSM categories and what to expect from each. If you're not familiar with shopping by GSM, it can seem a little tricky, but by the end, you'll have a clear understanding of which weight is right for you. Let’s dive in!

• GSM stands for Grams per Square Meter.
• It measures fabric weight, giving you a sense of how heavy or light the garment will feel.

GSM Categories:

1. 150 gsm - 180 gsm (Lightweight)
• Perfect for warmer weather or as a light layer.
• Depending on the color and weave, lighter garments might be slightly see-through (around 85% opacity).
• Example: The cuffs on our clothing are made from this weight. It rolls up easily and without adding too much bulk. We are working on designing some tees and sun hoodies in this weight for warmer seasons.
2. 190 gsm - 220 gsm (Midweight)
• A versatile option for all-season wear, commonly used for base layers.
• Great weight for all-around use against the skin, thin but provides ample warmth.
• Example: Most of our Signature Base Layers fall in this range—thin enough for everyday wear, yet warm enough to layer in colder months.
3. 230 gsm - 320 gsm (Heavyweight)
• Offers more warmth without being bulky. Ideal for colder weather or when you want something with extra weight.
• Even though it’s heavier, merino’s natural breathability keeps you from overheating.
• Example: Our Ultra Cozy Layers (265 gsm) feel lighter than cotton hoodies of the same weight but perform better in temperature regulation.
4. 330gsm - 600gsm (Outerwear)
• This is the heaviest range, perfect for snowy or extremely cold conditions.
• Merino wool keeps you warm even when wet, making it ideal for winter outerwear.
• Example: Think winter mitts, hats, and other heavy-duty gear. We don't offer anything in this weight currently... but we are working on it ;).

Same Thickness, Different GSM

Here’s an interesting fact: fabrics that feel the same in thickness can have different GSM ratings. How? It comes down to knitting density. Imagine knitting with fine needles versus chunky ones—both fabrics might end up the same thickness, but the fine-needle fabric will be denser, with more yarn packed in, leading to a higher GSM. This denser fabric will also be warmer and more durable, perfect for keeping your kids snug and well-protected in cooler weather.

images courtesy of The Fabric Store

Fabric Types: Jersey, Fleece, Woven, and Felt

While GSM tells you about the weight of the fabric, the type of weave or construction also plays a huge role in how the clothing feels and functions. Let’s explore the different merino wool fabric types and when to choose each one:

Jersey: Lightweight, stretchy, and super soft, jersey fabric is single-knit, making it perfect for everyday wear in warmer months. It’s breathable and flexible, allowing your child to move freely, whether they’re on a hike or lounging at home. Think of it like a cotton T-shirt but with merino wool’s superior moisture-wicking and temperature-regulating properties. Our Art Collage Tees are a great merino alternative to a cotton tee, perfect for hiking or layering under hoodies during shoulder seasons like fall and spring. Our Base Layers are also all made from merino jersey.

Sweatshirt Fleece: For a bit more warmth, sweatshirt fleece is the way to go. This fabric is double-knit, which means it’s thicker. It is smooth on one side and brushed on the other, provides more insulation and maximum coziness. Like your favorite cotton sweatshirt and sweatpants but with the breathability and warmth of merino wool! Our Ultra Cozy line is made from a merino sweatshirt fleece that is our kiddos absolute favorite!

Woven: Woven fabrics are less stretchy but incredibly strong and durable. This makes it perfect for pants, jackets, or outerwear—anything that needs to handle rough play or frequent washing. It’s sturdy and long-lasting while still offering the breathability that merino is known for. This is the woven wool we are familiar with for suitings and wool melton jackets.

Boiled: When you need serious warmth, boiled merino wool is your best bet. This knit fabric is made by creating a dense knit and then "boiling" it, compressing wool fibers together, creating a thick, dense material. Boiled wool is ideal for winter accessories like mittens and outerwear. Boiled merino wool is super warm and water-resistant, perfect for snowy or wet conditions.

Layering for Every Season

One of the best things about merino wool is its layering ability. You can mix and match different weights and fabric types to create the perfect outfit for any season.

Here are some examples:

• Pair a merino tee under a hoodie for the perfect everyday outfit for school or Fall hiking.
• Layer long sleeved tops and leggings under boiled wool outerwear for maximum warmth on colder days.
• For a super cold ski day, wear jersey base layers under sweatshirt fleece for doubled-up merino warmth. Pop you ski suit over, add a hat and neck gaiter, and you are set for a full day of outdoor fun!

Final Thoughts