GSM stands for grams per square meter, and it's the standard way the printing industry measures fabric weight. Every blank we offer has a GSM number attached to it in the product details, and it tells you more about how a shirt is actually going to feel than the brand name does. Here's what the number means and how to use it.
Think of it like paper
The easiest way to picture GSM is to think about paper weight instead of fabric. A 150 GSM shirt is roughly like standard printer paper — light and easy to move. Step up to 180 GSM and you're in brochure-paper territory: a bit more body, still flexible. At 207 GSM you're closer to a thick postcard — noticeably stiffer and more substantial. And 250 GSM is rigid cardstock territory — dense, structured, and heavy in your hands. Same idea applies to fabric: the higher the GSM, the thicker, denser, and heavier the shirt.
What the number is actually measuring
GSM measures how much the fabric weighs per square meter, which in practice comes down to how tightly the fibers are woven or knit together. A low-GSM shirt uses less material per square inch, so it drapes easily and breathes well. A high-GSM shirt packs more fiber into the same space, so it holds its shape, feels sturdier, and has more presence when you put it on. Neither end is "better" on its own — it depends on what you want the shirt to do.
GSM across our shirts
| Blank | GSM | Feel |
|---|---|---|
| Gildan 64000B (Youth) | 150 GSM | Light, soft, breathable |
| Gildan 5000 | 180 GSM | Classic midweight, durable |
| Gildan 5000B (Youth) | 180 GSM | Classic midweight, durable |
| O-neck Short Sleeve Tee | 180 GSM | Standard midweight |
| Comfort Colors C1717 | 207 GSM | Thick, soft, garment-dyed |
| Heavyweight Washed Tee | 250 GSM | Very thick, structured |
Why it matters when you're choosing a shirt
If you want something light that layers easily and breathes in warm weather, look toward the lower GSM numbers. If you want a shirt with more heft — the kind that feels premium the second someone puts it on, or holds up to heavier wear — go higher. For a deeper breakdown of exactly how each of our shirts feels and which one fits your project, check out our t-shirt brands guide.