GSM is a starting point
GSM stands for grams per square metre. It tells you how much fabric mass sits in a given area, which correlates with thickness, opacity and warmth. It does not tell you the yarn count, the knit structure, the shrinkage or the hand-feel.
Two fabrics can share the same GSM and behave completely differently. A compact ring-spun terry and a loose-knit fleece can both read 400 GSM, but one will hold a sharp silhouette while the other collapses. That is why a weight alone is not a fabric specification.
Same weight, different fabric
For hoodies and tracksuits, the construction matters as much as the number:
- Loopback terry: loops on the inside, lighter and more breathable than brushed fleece at the same weight.
- Brushed fleece: brushed inside for warmth and softness, with a denser surface and a heavier feel.
- French terry: smooth face with loops at the back; diagonal and high-density versions hold structure well.
- Compact ring-spun: tighter yarn and a denser surface, often used for a cleaner, more premium hand-feel.
If you want a structured hoodie that keeps its shape, the knit structure and the finishing matter more than pushing the GSM number higher. If you want warmth, brushed fleece at the same weight will feel warmer than loopback.
Weight by garment
The published ranges across our six categories give a practical starting point:
| Garment | Typical weight | What the weight does |
|---|---|---|
| Heavyweight tees | 260–300 GSM | Holds a boxy shape, supports dense print |
| Full-zip hoodies | 400–450 GSM | Structure without excessive bulk |
| Tracksuit sets | 380–450 GSM | Drape for flared or stacked legs |
| Pullover hoodies | 450–500 GSM | Heavy silhouette and warmth |
| Nylon windbreakers | 130–150 GSM | Light shell with DWR and lining |
| Varsity jackets | 600–700 GSM Melton | Body structure for patches and sleeves |
These are ranges, not rules. A cropped boxy tee may work at 260 GSM; a relaxed hoodie may feel right at 450 GSM. The silhouette and the intended season decide the target.
Wash, shrinkage and hand-feel
Heavyweight fabric is not automatically shrink-free. Cotton relaxes after washing, and an acid or stone wash changes the surface and the dimensions. The approved wash sample is what defines the bulk expectation.
Ask for the shrinkage result after the intended wash, not just the greige fabric weight. If the garment is garment-dyed or heavily washed, the pattern may need to allow for shrinkage so the finished measurements land on spec.
Hand-feel is also a finish decision. A carbon finish, an enzyme wash or a peached surface can make a heavy fabric feel softer without changing its weight. Specify the finish you want, not only the GSM.
Choosing for climate and season
A 500 GSM hoodie is a cold-weather product. A 280 GSM tee is a warm-weather product. Shipping both in the same container is normal, but the fabric choice should follow the market, not a single “heavy is better” assumption.
Consider how the garment will be worn: layered under a jacket, worn alone, or sold as a set. Consider the weight of the finished carton for air freight, and whether the fabric holds its shape on a hanger in a retail environment.
For nylon shells, lower GSM keeps the garment packable and light. For varsity jackets, the Melton weight is what gives the body its shape and supports chenille and appliqué.
How to specify weight on a tech pack
Write the specification as a combination, not a single number:
- Fabric type and construction, for example compact ring-spun terry.
- Composition, for example 100% cotton or a cotton/poly blend.
- Weight with a tolerance, for example 450 GSM ±5%.
- Finish, for example carbon finish or garment wash.
- Shrinkage expectation after the approved wash.
That combination is what a fabric supplier can quote and what a sample can be checked against. “Heavyweight” on its own is a mood, not a specification. Browse the catalog to see the published weights across the 19 styles.
