GSM (Grams per Square Meter)

GSM is grams of fabric per square meter — the single most useful spec on a tee. Rough bands: under 150 GSM is lightweight and often semi-sheer, 180–200 is a solid everyday weight, and 220+ is the "heavyweight" tee that holds its shape and structure. Higher GSM usually means more durable and more opaque, at the cost of summer breathability. It is the first number this site looks for, and the first one a founder-story brand tends to leave off the page. No published GSM is a fair reason to ask what you are paying for.