You will often see t-shirts described by their GSM — grams per square metre. It is simply a measure of how much the fabric weighs, and it tells you a lot about how a t-shirt will feel, drape and last.
Lightweight (130–160 GSM) t-shirts are soft, breathable and great for warm weather or layering, though they can be slightly sheer. Midweight (170–200 GSM) is the everyday sweet spot: substantial enough to hold its shape, light enough to stay comfortable year-round. Heavyweight (210 GSM and up) feels structured and premium, drapes with a clean line and tends to outlast everything else in the drawer.
There is no single best weight — it depends on the climate and the look you are after. If you want one t-shirt that does almost everything, a midweight cotton around 180 GSM is hard to beat.
