A metric unit of measurement defining the weight, density, and thickness of fabric.
GSM (Grams per Square Meter) is the metric standard used internationally to measure the weight and thickness of a knit or woven fabric. In apparel manufacturing, GSM is determined by cutting a precise 100-square-centimeter circular sample of fabric and weighing it on a calibrated digital GSM balance scale. A higher GSM indicates a heavier, denser, and generally thicker fabric, though it does not necessarily mean higher quality (yarn count and comb quality determine that). Understanding GSM ranges is critical for matching product lines with consumer expectations: 140 to 160 GSM is typical for lightweight, highly breathable promotional t-shirts; 180 to 200 GSM is the industry standard for retail-fit classic everyday t-shirts; 220 to 240 GSM is a heavy-weight fabric ideal for premium streetwear drop-shoulder t-shirts that require a structured, boxy drape; and 320 to 400 GSM is a high-density knit (often French Terry or fleece) used to manufacture premium hoodies, sweatshirts, and joggers that retain warmth and maintain structural shape.