GSM, grams per square metre, is the number brands quote most and explain least. It is simply how much a square metre of the fabric weighs. Higher means denser, not automatically better.
The rough scale
Around 140-160 GSM is a thin summer tee, light, often see-through after a few washes. 180-200 GSM is the standard high-street weight. 220-230 GSM, where we sit, is a proper heavyweight: opaque, structured, and it holds a shape instead of clinging.
Is heavy too hot for Dhaka?
This is the question we get most. Weight is not the same as breathability. A dense combed cotton with an open knit moves air better than a thin polyester blend. Because the cut is oversized, the fabric sits off the skin rather than against it, which is the part that actually keeps you cool.
Why it lasts longer
Heavier knits resist stretching at the collar and thinning at the shoulders, the two places a tee usually dies first. You pay a little more once instead of a little less three times.