GSM means grams per square meter and is the standard measure of fabric weight. A 200 GSM fabric weighs 200 grams per square meter of cloth. Lightweight sheers run from 40 to 90 GSM, mid-weight drapery from 150 to 250 GSM, and upholstery fabrics typically start above 250 GSM.
GSM bands and their uses
| GSM range | Category | Typical use |
|---|---|---|
| 40 to 90 | Sheer, voile | Light curtains, layering |
| 90 to 150 | Lightweight | Curtains, bed textiles |
| 150 to 250 | Mid-weight | Drapery, cushions |
| 250 to 450 | Heavy | Upholstery, wall covering |
| 450+ | Very heavy | Contract seating, outdoor bases |
An imperial ounce rating converts at 1 oz/yd² = 33.9 GSM, so an 8 oz fabric equals roughly 271 GSM, a heavy cloth by curtain standards and a mid-weight by upholstery standards.
Weight is not density
GSM measures mass; density counts threads per centimeter. Two fabrics with equal GSM can differ sharply in tightness and durability, which is why Sarelli specifications list composition, width and repeat alongside weight. The distinction is covered in fabric weight vs fabric density. Sarelli weaves sheer curtain articles from 40 to 90 GSM, described in the sheer fabrics production guide, and upholstery jacquards in the luxury fabrics collection.