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. 

Specify ±3% against nominal GSM as a minimum, and state the inspection method so the tolerance is testable — that means referencing ISO 9073-1 for mass per unit area and agreeing how many specimens, cut where, and how the worst case is judged. A tolerance without a test method is not a specification. Ask for the per-roll GSM record with the shipping documents, and treat any refusal to commit to a tolerance in writing as a signal about how the next claim will be handled.

Because GSM is what selects the customs subheading, and the subheading is what sets your duty rate. Four documentation habits keep clearance to a single pass: keep the product name and HS code identical across the commercial invoice, packing list and bill of lading — never "nonwoven fabric" on one document and "PP material" on another; fix one code per SKU, and change it when the GSM changes; watch SKUs sitting at a band edge, such as exactly 70 g/m², where a small tolerance shift can move the classification; and keep a third-party GSM test report on file so a customs exam can be answered immediately.

Almost all spunbond, meltblown and other fibre-web nonwovens sit under HS heading 5603. For man-made filament nonwovens — which includes PP spunbond and SMS — the subheading then splits on mass per unit area:

up to 25 g/m² → 5603.11  |  over 25 up to 70 g/m² → 5603.12  |  over 70 up to 150 g/m² → 5603.13  |  over 150 g/m² → 5603.14

Note the practical consequence: a 120 g/m² bag lining and a 25 g/m² crop cover are different tariff lines. Confirm the destination-specific duty before you ship rather than after, because the same 5603 heading carries very different MFN rates in different markets. 

Roll goods are normally priced per kilogram or per tonne, not per metre, because the weight of a roll is what the resin in it costs. A per-metre or per-square-metre price is usually a conversion of the same kilogram price at a stated GSM and width. This produces a common trap: a supplier quoting a lower price per metre may simply be shipping a lighter GSM or a narrower width. When you compare offers, convert everything to cost per kilogram at identical GSM and width, and compare the landed cost after freight and surcharges rather than the ex-works number.

Being straight about these saves a failed order. Spunbond has lower tear and tensile strength than woven fabric at equal weight; standard PP grades have limited heat resistance and will distort well below the temperatures a polyester fabric tolerates; unstabilised PP degrades under UV outdoors; it is not elastic unless you specify an elastic grade; it is not a barrier fabric on its own, so anything needing liquid or particle protection requires a meltblown layer (SMS/SMMS) or a coating; and because colour comes from masterbatch rather than dyeing, batch-to-batch colour matching is a specification item, not an assumption.

Sometimes, and only on a like-for-like test. Spunbond is a good substitute for woven fabric where fraying, weight, dust generation or cost dominate and where a lower tear strength is acceptable — that is precisely the bag-lining case. It is a good substitute for film where breathability, drape or a textile hand-feel is wanted rather than a total moisture barrier. It is the wrong substitute where high tear strength, high load or a guaranteed liquid barrier is the requirement; those stay with woven, coated or spunmelt-barrier constructions. Always compare both machine-direction and cross-direction tensile before substituting, because spunbond is anisotropic.