Specifications & Testing
Wool Fabric GSM: Select Weight and Check g/m vs g/m²
What GSM should a buyer request for wool fabric?
The weight number matches, but the cloth feels wrong. Why?
GSM means grams per square metre. It describes mass per area, not thickness, softness or a guaranteed temperature rating. Two woolen fabrics with the same GSM can behave differently because their yarns, construction and finish differ.
Check the unit before changing the specification
A weight stated in g/m is per linear metre and depends on width. GSM multiplied by measured width in metres gives grams per linear metre when both use the same fabric and measurement basis. Confirm whether selvedges are included; a number without its unit or width cannot be compared reliably.
Choose against the actual coat design
Bring the intended length, silhouette, lining, interlining and layering requirements to the sample review. Examine a draped or sewn panel for hanging shape, seam bulk and movement. Warmth also depends on the complete garment and use conditions, so a single GSM threshold cannot establish comfort for every climate.
Confirm the finished cloth rather than one small swatch
Agree conditioning, measurement method, positions and the permitted range. Review individual measurements across representative finished rolls, not only an average. If weight and width move together, examine the finishing condition before correcting one number in isolation. Reapprove the sewn trial when a construction or finish changes.
When can the order move forward?
Proceed with an identified physical reference, the correct weight unit, finished-width basis and agreed tolerances. Record the garment trial outcome alongside GSM; do not accept a heavier substitute solely because its number is higher.
Fred Textile
Send Fred Textile your coat or jacket sketch, target handfeel, lining plan, weight unit, width, quantities and reference cloth. Ask for suitable physical samples and article-specific finished weight data.
mrkcal@fredtextile.comPractical sourcing decision
Why 600 g/m is not 600 GSM
GSM means grams per square metre. Grams per linear metre measures a one-metre length at the fabric's stated width. Therefore width is required when comparing the two units. Ask whether the weight measurement uses total or usable width and keep that basis consistent. Shipping gross weight includes packaging and is not the same as the fabric-only calculation below.
| Decision | Option or check | What to compare |
|---|---|---|
| g/m to GSM | GSM = grams per linear metre ÷ width in metres. | 600 g/m ÷ 1.50 m = 400 GSM. |
| GSM to g/m | g/m = GSM × width in metres. | 400 GSM × 1.50 m = 600 g/m. |
| GSM to oz/yd² | oz/yd² = GSM ÷ 33.9057. | 400 GSM is approximately 11.80 oz/yd². |
Put the decision into practice
For 1,000 metres at 400 GSM and 150 cm width, estimated fabric mass is 400 × 1.5 × 1,000 ÷ 1,000 = 600 kg. This is a mathematical estimate before roll cores, wrapping and other packing. Use measured packed dimensions and gross weights for freight quotations; do not substitute this estimate for a packing list.
Fabric GSM and roll-weight calculator
Enter the weight per linear metre and the matching finished width. The same width basis must be used throughout.
Formula: GSM = g/m ÷ width in metres. oz/yd² = GSM ÷ 33.9057. Net kg = g/m × length ÷ 1,000. An area ounce is not an ounce per linear yard.
Estimates exclude packing, tubes and moisture variation. Use measured finished fabric values for order approval; this is not a price or shipping quotation.
Your next buying question
Discuss your fabric with Fred Textile
Send your reference, garment use, composition, finished weight and width, colour quantities and target delivery. Ask which sample and production route can be supported for your project.
mrkcal@fredtextile.comDecisions for this fabric question
- Garment silhouette
- Construction and loft
- Season and lining
Evidence and specification checklist
- Target finished GSM
- Test method and conditioning
- Allowed tolerance
- Full-width sample weight
Mistakes and practical controls
Quoted GSM is a nominal greige value
Require finished-fabric data
One cut is not representative
Test across width and rolls
Higher GSM is assumed warmer
Compare structure and air retention
Fred Textile
Fred Textile manufacturer context
Fred Textile is the operating brand of Fengruide (Suzhou) Textile Technology Co., Ltd., a woven woolen and blended fabric manufacturer in China. Composition, tests, certification scope, price, MOQ and delivery require written confirmation for the actual order.
FAQ
Practical buyer guide
What GSM should a buyer request for wool fabric?+
There is no universal correct GSM. Set a target range from the garment, construction, climate and finish, then confirm conditioned test results and tolerance. Compare fabrics with similar structures rather than treating weight alone as warmth.
Which decisions change the right wool fabric GSM specification?+
The main decision variables are Garment silhouette, Construction and loft, Season and lining. Define them against the garment, wearing climate, care route and target market before comparing samples. A supplier should explain how the proposed construction and finish deliver those outcomes, and the buyer should retain a conditioned physical reference for bulk comparison.
What should an RFQ and bulk approval include for wool fabric GSM?+
Include Target finished GSM, Test method and conditioning, Allowed tolerance, Full-width sample weight. State the test or inspection method, unit, tolerance, sample stage, quantity by colour, intended garment and approval owner. Before bulk release, review these predictable risks: Quoted GSM is a nominal greige value: Require finished-fabric data. One cut is not representative: Test across width and rolls. Higher GSM is assumed warmer: Compare structure and air retention.