GSM guide: which fabric weight for which garment.
What GSM actually measures, the weight bands we use for tees, hoodies, polos and joggers, and what changes when you go heavier. Written from the factory floor in Tirupur.
What GSM means
GSM is grams per square metre: the weight of one square metre of that fabric. A 300 GSM fleece means a square metre of it weighs 300 grams. It is a density figure, not a quality figure, and that distinction is where most first-time briefs go wrong.
Two fabrics at the same GSM can feel completely different. A 300 GSM fleece is airy and lofty because brushing traps air. A 300 GSM jersey is dense and flat because the same weight is packed into a thinner sheet. So GSM tells you how much yarn is in the fabric, and the construction tells you how that yarn behaves.
Use GSM as shorthand you and your factory agree on, then confirm it with a physical sample. Nobody buys a garment because of a number on a spec sheet.
See all fabrics we manufacture in →// Quick answers
How GSM is checked in a factory
Three checks, and the reason your bulk can land a little off your sample.
The cut and weigh test
A round cutter takes a disc of known area from the roll, the disc goes on a precision balance, and the reading converts to grams per square metre. It is done on incoming fabric.
Conditioned, not damp
Cotton holds moisture, so fabric is checked after it has settled. A roll weighed straight off wet finishing reads heavier than it will a day later.
Tolerance is normal
Knitted fabric moves. A tolerance of roughly five per cent either side of the target is standard across the industry, and it shifts again after dyeing and compacting, so we quote a band rather than an exact figure.
Ask for the fabric inspection note with your sample. Our QC works to AQL 2.5 under ISO 9001 certified quality management, and inspection reports are available on request. See quality assurance.
Which GSM for which garment
The bands we quote most often, with what each one is actually for.
// T-shirts
Pages: t-shirt manufacturing, oversized tees, cotton jersey.
// Hoodies & sweatshirts
Pages: hoodie manufacturing, sweatshirts, French terry, fleece.
// Polo shirts
// Joggers & shorts
Pages: joggers manufacturing, shorts, co-ord sets.
// Leggings & activewear
Pages: leggings manufacturing, women's athleisure.
// Premium fibre options
Pages: Supima cotton, organic cotton.
Six things GSM decides for you
Drape
Light fabric follows the body and moves. Heavy fabric stands away from it and holds the line of the pattern. If you have drawn a boxy, architectural shape, weight is what makes it read that way on a person.
Opacity
Show-through is a returns problem, especially in white and pastels. Heavier knits hide more, but construction and yarn count matter as much. Check opacity on the actual colour, not on black.
Shrinkage
Heavier knits carry more yarn, so shrinkage shows up as a bigger absolute change. We control finishing to keep it inside a stated tolerance and build the allowance into the pattern.
Print results
Flat, denser surfaces hold fine detail. Brushed and looped surfaces soften edges, so bold artwork, puff and embroidery work better there. Sublimation needs polyester content regardless of weight. See decoration methods.
Shipping cost
Air freight is billed by weight, so moving a hoodie from 300 to 400 GSM changes the cost of every unit shipped. Sea freight is billed by volume, and heavy knits are bulkier too.
Unit price
Fabric is the biggest line in a knitwear quote. More yarn per metre means a higher cost per piece before a single stitch is sewn. A jump of 60–80 GSM is a real cost decision, not a detail.
Common GSM mistakes
These come up in almost every first brief we review. None of them are expensive to fix at the brief stage, and all of them are expensive to fix after bulk fabric is knitted.
- Choosing heavy GSM for a hot market. A 400 GSM fleece hoodie is a great product in a northern winter and unsellable in a humid city for nine months of the year. Match the weight to where your customer lives, then use a 280–300 GSM terry if you need a year-round hoodie.
- Expecting a 180 GSM tee to hold an oversized boxy shape. Light jersey collapses onto the body. The drop shoulder droops, the hem clings, and the photos look nothing like the moodboard. Boxy cuts need 240 GSM and up, with the pattern cut for that weight.
- Treating GSM as a quality score. Yarn, knitting and finishing decide how a garment ages. A well-made 200 GSM tee in Supima outlives a coarse 300 GSM one.
- Comparing GSM across different constructions. A 300 GSM fleece and a 300 GSM jersey are not the same product. Compare like with like, or compare samples in the hand.
- Skipping the physical sample. Approving a spec sheet without feeling the fabric is the single most common cause of a second sample round and a delayed launch.
// Getting it right
GSM: common questions
180–220 GSM for a comfortable everyday tee, 240–320 GSM for a structured premium or oversized tee. Below 160 GSM the tee reads as event merch rather than a brand piece. See t-shirt manufacturing.
280–340 GSM in French terry for a hoodie that works most of the year, 340–400 GSM in brushed fleece for a heavyweight winter piece. Both need heavy rib at cuff and hem. See hoodie manufacturing.
No. Higher GSM means more yarn, more warmth, more structure, more cost and more freight. It says nothing about yarn quality or finishing. Pick the weight the garment and the market need, then spend the rest of the budget on construction.
Slightly. Fabric relaxes and compacts in the first washes, which can read as a small weight change per square metre. We pre-treat and compact to control it, and build the shrinkage allowance into the pattern.
140–180 GSM tees, 180–200 GSM polos and 280 GSM terry as the heaviest top layer. Keep fleece for winter ranges or for markets with a real cold season. See markets we serve.
Surface matters more than weight. Flat jersey holds fine detail for DTG and screen work, while brushed and looped surfaces suit puff, embroidery and bold blocks. Screen printing runs through vetted partner units, managed by our QA team. Compare methods on decoration.
Pick the weight with a sample in your hand.
Tell us the garment, the silhouette and the market, and we will recommend a GSM and send a sample. From 50 pieces per colour.