GSM means grams per square metre. It is a weight, not a quality score: a light poplin and a heavy flannel can both be well made.
What the number changes
Light fabric, roughly 100–140 GSM, is cool and slightly more transparent, which suits summer and layering. Mid-weight, around 140–180 GSM, is the year-round shirt: opaque enough to wear alone, light enough indoors. Heavy fabric, 180 GSM and up, drapes more, wrinkles less and feels warmer — good for overshirts and cooler months.
What it does not tell you
GSM says nothing about weave quality, stitching or fit. A heavy shirt with a poor shoulder seam will still hang badly. Read the weight together with the material and the measurements on the product page.
Our listings name the material and the measurements for each style. One piece minimum, dispatch within 24 hours, 7–12 working days delivery, 14-day returns.
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