T-Shirt Quality Decoded: GSM, Cotton Blends & Stitching
GSM (grams per square metre) tells you how heavy a fabric is. Around 140–160 GSM feels light and suits hot summers, 180–200 GSM is a durable everyday weight, and 220 GSM and above feels thick and structured. Combine the right weight with combed or ring-spun cotton and neat seams, and you have a tee that keeps its shape.
Last reviewed: 27 October 2026
GSM explained
| GSM | Feel | Best for |
|---|---|---|
| 120–150 | Very light, may be see-through in light colours | Undershirts, peak summer |
| 150–180 | Light to medium | Everyday summer tees |
| 180–200 | Medium, holds shape | Year-round basics |
| 200–240 | Heavy, structured | Oversized and streetwear styles, cooler months |
Higher GSM is not automatically better; it is just heavier. Pick the weight for your climate and style.
Cotton types
- Carded cotton: basic process, more short fibres, can pill and feel rougher.
- Combed cotton: short fibres removed, smoother and stronger.
- Ring-spun cotton: twisted yarn that is soft and durable.
- Cotton-poly blends: dry faster and shrink less; less breathable.
- Cotton with elastane/lycra: adds stretch for fitted styles.
Construction details
- 1
Collar
A ribbed collar with a little lycra keeps its shape. Check that it lies flat.
- 2
Shoulder tape
Tape along the shoulder seam stops stretching.
- 3
Side seams vs tubular
Side-seamed tees usually fit better; tubular tees can twist.
- 4
Hem stitching
Double-needle hems are more durable.
Shrinkage and colour
Look for 'pre-shrunk', 'bio-washed' or 'enzyme-washed' in descriptions. Even so, wash in cool water first time and dry flat or in shade. Wash bright colours separately at first to check for bleeding.
Frequently asked questions
The listing doesn't show GSM. What should I do?
Ask the seller. If they cannot tell you, look at reviews mentioning thickness, or check whether the photos show light passing through the fabric.
Why do some tees twist after washing?
Usually because of fabric cut off-grain or tubular construction. Better-made tees are less prone to it.
Building a full wardrobe?
See the capsule guide