Selection · 6 min read
How to choose fabric weight (GSM) for your product
Start from the garment, not the number. Weight decides drape, opacity and how long the piece survives washing — so it is the first spec to fix, before composition and before price.
Typical weights by garment
These are working ranges, not rules. The same garment can sit at either end depending on the market and the season.
| Garment | Typical weight | Note |
|---|---|---|
| Light shirting (voile, lawn) | 80–110 gsm | Sheer; needs a lining or a layered look |
| Poplin shirting | 110–140 gsm | The safe default for dress shirts |
| T-shirt, light | 130–150 gsm | Summer, promotional, warmer markets |
| T-shirt, standard | 150–180 gsm | Most retail programmes |
| T-shirt, heavyweight | 200–240 gsm | Structured drape, streetwear |
| Polo / pique | 180–220 gsm | Below 180 it collapses at the collar |
| French terry | 240–320 gsm | Loungewear, mid-layer |
| Hoodie fleece | 280–400 gsm | Above 350 gets expensive to ship |
| Chino / bottom-weight twill | 240–320 gsm | Below 240 shows through at the knee |
| Denim | 10–14 oz (340–475 gsm) | Ounces are the trade unit here |
| Linen shirting | 120–180 gsm | Washed linen reads heavier than greige |
| Canvas / jacket | 300–450 gsm | Check the mill's max for your construction |
Why weight comes before composition
Composition tells you how the fabric behaves; weight tells you what the garment becomes. A 120 gsm cotton and a 240 gsm cotton are different products even though both are "100% cotton". If you specify composition first, you will get quotes that look comparable and garments that are not.
The number most quotes leave out: tolerance
Mills quote a nominal weight. What arrives is a range. For knits, ±5% is normal; for wovens, ±3%. Ask for the tolerance in writing, and check the first bulk roll against it — not the sample.
Also ask whether the weight is quoted greige (before dyeing and finishing) or finished. Finishing can move weight by 5–10%, which is enough to change the hand-feel you approved.
How to choose in three steps
- Pick the garment and the market. A heavyweight tee for Germany and a light tee for Australia are not the same brief.
- Pick the weight band from the table, then adjust for season and price target.
- Ask for two weights, not one. Comparing 160 and 180 gsm samples side by side is the fastest way to make the decision.
What this means for sourcing
Put the weight, the tolerance and the greige-or-finished basis in the enquiry. Mills quote more accurately, and you get fewer surprises at inspection. If you are not sure which band fits your product, send a reference garment — we will match it against what the mills actually run.
FAQ
Is GSM the same as oz?
No, but they convert. 1 oz/yd² is about 33.9 gsm, so 180 gsm is roughly 5.3 oz. US buyers usually quote ounces for knits, Europe and Asia quote grams.
Does a higher GSM always mean better quality?
No. Weight tells you how heavy the fabric is, not how well it is made. A 240 gsm tee in low-grade yarn pills faster than a well-knitted 180 gsm one.
How much tolerance should I accept on weight?
A tolerance of about ±5% is normal for knits and ±3% for woven. Ask for the tolerance in writing and check the first bulk roll against it.