Added 2026-10-21 from trending overseas buyer search questions. We update this centre daily.
A fabric's value, care and compliance all ride on its fibre content. Before bulk, most buyers need to answer two things: does the cloth match the composition we agreed, and is the blend on the label legally defensible? Most markets (EU, US, and others) require an accurate fibre-content label, so a wrong or vague claim is not just a quality issue — it is a compliance one. A 30-second check at the sample stage can flag an obvious mismatch before you pay for a container.
Fibre identification splits into two jobs, and buyers confuse them constantly:
A burn test answers "what". It cannot reliably tell you "how much" — a 65/35 and an 80/20 cotton–polyester will both burn and melt. For the percentage you need a quantitative standard method.
| Standard | What it does |
|---|---|
| AATCC 20 | Fibre analysis — qualitative: microscopy, burn behaviour, solubility and other screens to name the fibres. |
| AATCC 20A | Fibre analysis — quantitative: chemical separation / microscopy to give percentages. |
| ISO 1833 series (incl. ISO 1833-1:2020) | Quantitative analysis of fibre mixtures; the global reference, often with a chemical-dissolution step. |
| ASTM D629 | US chemical test methods for quantitative fibre analysis. |
| GB/T 2910 | China's national series, equivalent to ISO 1833. |
These are the method names a serious mill or testing lab works to. When you compare two suppliers, compare the method and version they tested under, not just the headline percentages.
A burn test is a legitimate first screen on a loose yarn or clipped fibre — never on a finished garment, and only in a safe, ventilated space. Pull a few fibres, hold them with tweezers, and watch four things: does it melt, the smell, the smoke, and what the residue looks like.
| Fibre | Behaviour near / in flame | Odour | Residue |
|---|---|---|---|
| Cotton / linen | Burns fast, no melt | Burning paper | Soft grey powdery ash |
| Viscose / rayon (regenerated cellulose) | Burns very fast, no melt | Burning paper | Light, soft ash |
| Wool / silk (protein) | Shrinks, burns slowly, may self-extinguish | Burning hair | Black brittle bead, crushes to dust |
| Polyester | Melts then burns, sooty flame | Sweet / aromatic | Hard dark bead, will not crush |
| Nylon | Melts, shrinks, then burns | Celery / amino | Hard light-brown bead |
| Acrylic | Melts and burns readily, smoky | Acidic, sometimes fishy | Hard brittle ash |
Limitations to keep honest: the burn test is qualitative, works best on a single fibre, and a blend will show mixed signs (cotton burns, polyester melts). It is a screen, not proof. Where the exact ratio matters, send it to a lab under ISO 1833 or AATCC 20A.
When a precise answer is needed, a laboratory combines methods:
This is why a composition claim with a named method and a third-party report is worth far more than a number typed on a spec sheet.
We state composition on every order specification and can arrange third-party testing against the named standard, with the report available on request. Our own fibre-related certificates — OEKO-TEX, GRS, GOTS, OCS, BCI — are held and their verification details are available on request. As an integrated woven mill (yarn dyeing → weaving → fabric dyeing → printing → finishing) we develop the cloth in-house; sampling is charged and credited against your bulk order, MOQ is 2,000 metres per colour, and bulk lead time is confirmed in writing at enquiry. For a fibre-content check on your swatch, write to gxy@ntboerli.com.
No. The burn test is qualitative: it shows which fibres are present, not how much of each. For a precise percentage you need a quantitative method such as ISO 1833 or AATCC 20A. A blend will simply show mixed behaviour — cotton burning, polyester melting.
For a defensible claim, ask for the test method and, where it matters, a third-party test report. A label percentage is only as reliable as the method and lab behind it.
We state composition on every order specification. Where an independently verified figure is required, we arrange testing against the named standard and provide the report on request — we do not present an in-house number as a substitute for accreditation.
For North America use AATCC 20 (qualitative) and AATCC 20A (quantitative); for the EU and Asia use the ISO 1833 series (GB/T 2910 in China is equivalent). Always name the method and version so two mills' results are comparable.