How is GSM measured and verified?

Six claims account for most disputes, and all six are preventable at the specification stage: GSM drift between batches — contract a tolerance and require per-roll records; uneven web with thin streaks or thick lanes — inspect a 1 m section on a light box before the run is released; colour variation between batches — seal a reference sample and approve each batch against it; roll geometry and winding faults that disrupt line feeding — specify diameter, core and tension, and seal a reference roll; moisture damage in transit — require moisture barrier packing and container desiccant; and lamination failure — run a bonding trial at production temperature and check for strike-through, bubbles and delamination before releasing the balance of the order.

There is no universal MOQ for spunbond, and any supplier quoting one number for everything is simplifying. MOQ is driven by whether you take a stock specification or a custom one: stock GSM, width, colour and bond pattern can normally be shipped in small quantities, while a custom colour, a special blend, a bespoke width or a new embossing pattern is tied to a minimum production run because the line has to be set up and cleaned. Ask for those two numbers separately. The same logic applies to lead time — a stock spec is quoted in days, a custom run in weeks — and the Incoterm you choose should follow your own freight capability rather than the supplier's convenience.

The trade-off is accountability versus reach. A direct factory gives you price without intermediary margin, tolerances traceable to its own line, and the ability to prioritise your order inside its own production schedule. A trading company can be useful for very small mixed orders or when you need many unrelated products consolidated, but for a technical substrate you inherit the mill's lead times and quality variation without inheriting the mill's accountability. If you buy through a trader, at minimum name the mill in the contract and require its mill test certificates.

Use three structured video audits instead of a brochure, then prove the spec on samples: (1) running-line production with live GSM readings taken on camera; (2) raw-material and masterbatch sourcing, explaining which resin and regrind blend suits which application and where the cost difference comes from; (3) the QC laboratory, running weight, tensile and elongation tests on camera. Follow it with a multi-spec sample pack tagged with GSM, blend, bonding temperature and trial pressure so the samples can be run on your own line. Only then place a trial order — and only one container of it.

If it is missing any of these twelve lines, the quotation is not yet a specification: 1) polymer type; 2) GSM with tolerance; 3) width with tolerance; 4) colour and colour-consistency requirement; 5) bond pattern or embossing reference; 6) tensile strength and elongation with the test method stated; 7) roll diameter, length and core size; 8) winding tension or a sealed reference sample; 9) packing and palletising; 10) HS code; 11) certifications; 12) MOQ, lead time and Incoterm. Items 6 and 9 are the two most frequently omitted and the two that generate the most arguments at destination.

Match the certificate to the end use rather than collecting logos. OEKO-TEX® STANDARD 100 is the one retail buyers reference first when harmful-substance testing is required, because it covers the article itself; buyers should always require a valid certificate and check the label number and issuing certification body. ISO 9001 covers the manufacturing system. Where recycled content is claimed, ask for the applicable recycled-content certification and make sure the claim on the certificate matches the claim on your packaging.