Most t-shirts look fine on a hanger. The real test is everything that comes after — the first wash, the tenth wash, six months of regular wear.
Here’s how to tell the difference before you buy.
1. Check the GSM
GSM (grams per square metre) is the single most useful number when evaluating a t-shirt. It tells you how dense and heavy the fabric is.
- Under 180 GSM — thin, see-through, short lifespan. Fine for gym wear, not for a wardrobe staple.
- 180–250 GSM — mid-weight. Decent, but will soften and lose shape over time.
- 280–320 GSM — heavyweight. Holds structure, drapes well, lasts.
- 320+ GSM — premium heavyweight. The benchmark for a t-shirt built to last years.
Most brands don’t advertise GSM because it exposes how little fabric they’re actually using. If you can’t find it, that’s a signal.
2. Hold It Up to the Light
A quick test: hold the t-shirt up to a light source. If you can see your hand clearly through the fabric, it’s too thin. A quality heavyweight tee should be opaque — no light bleed, no transparency.
3. Look at the Shoulder Seam
The shoulder seam placement tells you a lot about how intentional the fit is. On a well-constructed oversized tee, the seam should sit at or past the natural shoulder — not pulled inward or sitting on the arm.
A seam that’s in the wrong place means the garment was sized up from a standard pattern, not designed for the silhouette.
4. Check the Stitching
Flip the t-shirt inside out and look at the seams. Quality construction uses:
- Double-needle stitching on the hem and sleeves — two parallel stitch lines that prevent curling and add durability
- Taped or reinforced shoulder seams — reduces stretch and distortion over time
- Clean, even stitch tension — no puckering, no loose threads
Loose threads and single-needle hems are signs of cost-cutting in production.
5. Read the Fabric Composition
100% cotton or a cotton-rich blend (at least 80% cotton) is the standard for a quality basic. Cotton breathes, holds dye well, and softens naturally over time without losing structure.
Watch out for high polyester content in basics — it’s cheaper to produce, pills faster, and doesn’t age well. It also holds odour more than cotton.
6. Check the Collar Construction
The collar is usually the first thing to go. Look for:
- Ribbed collar with a tight, dense knit — it should spring back when stretched
- Reinforced collar tape on the inside — prevents the neckline from stretching out
- A collar that sits flat without curling or folding
If the collar looks slightly off on the hanger, it’ll look worse after washing.
7. Feel the Weight in Your Hand
This sounds obvious, but hold the t-shirt and feel it. A quality heavyweight tee has substance — it has a satisfying weight and drape. It shouldn’t feel papery, flimsy, or insubstantial.
If it feels light, it probably is.
The Summary
| What to Check | What to Look For |
|---|---|
| GSM | 280+ for heavyweight |
| Light test | Opaque, no transparency |
| Shoulder seam | At or past natural shoulder |
| Stitching | Double-needle, clean tension |
| Fabric | 100% cotton or cotton-rich |
| Collar | Ribbed, reinforced, sits flat |
| Hand feel | Substantial weight and drape |
A good t-shirt isn’t complicated. It’s just fabric, construction, and fit — done properly. The brands that get all three right are the ones worth buying from.
Shop Donestate’s heavyweight tees in T-shirts, starting with the 420 GSM Heavyweight Boxy T-Shirt.
Want the numbers side by side? Our fabric weight chart lists the GSM of every Donestate piece, from light summer shirts to 543 GSM denim. Or go straight to everything 300 GSM and up.