GSM

GSM (Grams per Square Meter) is the international standard unit for measuring fabric weight, expressing how much one square meter of fabric weighs in grams. This straightforward measurement provides immediate insight into a fabric's density, thickness, and substance—higher GSM indicates heavier, more substantial fabric, while lower GSM indicates lighter, more sheer material.

Measuring GSM is simple and precise. Cut a 10 cm × 10 cm sample (100 cm²), weigh it on a precision scale, and multiply by 100 to get the GSM value. Alternatively, use a GSM cutter—a die that punches out exactly 100 cm² samples—for consistent, repeatable measurements. Quality control labs typically test multiple samples from different areas of a fabric roll to account for any variation.

Several factors determine a fabric's GSM. Fiber type plays a role—denser fibers produce heavier fabrics at the same construction. Yarn count affects weight, with finer yarns generally producing lighter fabrics. Weave density directly impacts GSM, as more threads per unit area means more material. Finishing treatments can also alter weight, with some processes adding substances (like coatings) that increase GSM, while others (like singeing) may slightly reduce it.

For buyers, GSM serves multiple purposes. It indicates quality and durability—within a fabric type, higher GSM often correlates with longer-lasting products. It affects drape and hand feel, with lighter fabrics flowing more freely and heavier fabrics providing more structure. GSM helps determine suitability for specific applications; a 90 GSM fabric works well for lightweight summer bedding but would be too insubstantial for upholstery. Finally, GSM directly impacts cost, as heavier fabrics require more raw material. When combined with thread count and denier specifications, GSM provides a complete picture of fabric construction.