Velvet guide
Velvet Fabric GSM: A Practical Guide to Weights
GSM is the first number most buyers ask for and the one most often misread. It tells you how much fabric you are buying per square metre, not how good it is. A 260 gsm velvet with a dense short pile and a 260 gsm velvet with a thin pile on a heavy backcloth are different products at the same weight. This guide explains what GSM covers, the usual bands for velvet, and what else belongs in the spec.
What GSM actually measures
GSM is grams per square metre: the mass of one square metre of finished fabric. It is measured by cutting a conditioned specimen of known area and weighing it, under ISO 3801 or ASTM D3776. GSM is independent of width, which is why it is the right figure for comparing qualities. Grams per running metre is not. A 44-inch and a 58-inch quality at the same gsm weigh very different amounts per metre, because the running metre is wider. If a supplier quotes weight per metre or per than, ask for the width so you can convert back to gsm before comparing.
Typical GSM bands for velvet
As a rough map of the market: 120-160 gsm covers brasso and burnout qualities on a sheer ground; 160-180 gsm covers knitted two-way stretch velvet; 180-240 gsm covers viscose velvet; 200-280 gsm covers printed polyester velvet; 200-300 gsm covers micro velvet; and 250-320 gsm covers cotton velvet. Upholstery qualities generally start around 300 gsm and go higher, sometimes with a back-coating included in the stated figure. The bands overlap. A heavy dress velvet can weigh the same as a light furnishing velvet and behave nothing like it, so treat these as orientation, not as grades.
GSM, pile density and drape
GSM is the total of the ground weave, the pile, and any backing. That is why two 260 gsm velvets can be completely different: one with a dense short pile on a light ground, the other with a thin pile on a heavy backcloth. The first covers better and wears better. The second is stiffer and lets the ground show through the pile. What you actually feel is pile density, counted as tufts per square centimetre or pile ends per inch, together with pile height. Drape follows fibre and yarn fineness more than weight. A 200 gsm viscose velvet falls more softly than a 200 gsm cotton one.
GSM, durability and price
Heavier velvet usually costs more per metre because it contains more yarn, and yarn is bought by weight. Price also carries the fibre, the dyeing and the finishing, so a light viscose quality can cost more than a heavier polyester one. Durability is not a function of gsm either. Abrasion resistance comes from fibre type, pile density, how firmly the pile is bound into the ground, and whether the back is coated. Ask for a Martindale (ISO 12947) or Wyzenbeek (ASTM D4157) result on the exact quality you are buying rather than reading weight as a proxy for wear.
How to specify GSM on an order
State the gsm, the tolerance and the stage it applies to. A tolerance of about plus or minus 5 per cent on finished goods is normal commercial practice, but agree it in writing. Say whether the figure is greige or finished, because dyeing, brushing and back-coating all change it. Confirm the usable width the gsm relates to and whether any coating is included in it. Then approve a cut sample against that spec and keep a sealed swatch for reference at delivery. Knitted pile velvet is classified under HSN 6001; confirm the heading for woven qualities with your supplier before shipping.
Why GSM alone is not the whole spec
A complete velvet spec runs to eight or nine lines, not one. Fibre and filament fineness. Pile height in millimetres. Pile density. Ground construction and how the pile is anchored. Backing or coating. Finished width. Finish, whether plain, crushed, embossed or printed. Colourfastness to rubbing and light, tested to the ISO 105 series. Dimensional stability after washing or dry cleaning. GSM tells you roughly how much fabric you are buying. The rest tells you how it will look after six months on a sofa or six wears on a garment. Suppliers such as Shailesh Velvet Industries will sample against a written spec before bulk.
Frequently asked questions
What GSM is best for sofa upholstery velvet?
Most furnishing velvets sit at 300 gsm and above. At the same weight, a dense short pile wears better than a long one, so confirm the choice with an abrasion test result rather than weight alone.
What GSM suits dress and saree velvet?
Roughly 120-240 gsm. Brasso runs 120-160 gsm, knitted stretch velvet up to about 180 gsm, and viscose velvet 180-240 gsm, which drapes well for sarees, gowns and dupattas.
Is higher GSM always better quality?
No. Weight can come from a heavy backcloth or a coating rather than from pile. A denser pile on a lighter ground often covers better, feels richer and lasts longer than a heavier, thinly piled cloth.
Does GSM change with fabric width?
No. GSM is mass per square metre, so it reads the same at 44 or 58 inches. Weight per running metre does change with width, which is why gsm is the safer basis for comparison.
