Short answer: Textile blends are classified using a hierarchy: for most textile products, the fiber that predominates by weight determines the classification, and specific section notes dictate the tie-breaks when no fiber dominates. Apparel brands get this wrong by classifying on the fiber they market, the fiber on the label, or the fiber they remember from the tech pack, rather than the actual weight breakdown. The fix is getting lab-verified fiber content for every blended SKU and applying the section notes mechanically.
The predominance rule
Section XI of the tariff, which covers textiles, generally classifies fabrics and many made-up articles by the textile material that predominates by weight. A fabric that is 60 percent cotton and 40 percent polyester is a cotton fabric for classification purposes, regardless of which fiber the brand considers the hero ingredient.
Weight means actual weight, not label order or marketing emphasis. Labels list fibers in descending order by weight, which is a useful starting point, but labels can be wrong, rounded, or based on the design spec rather than the production reality. The classification follows the goods as made, not as described.
For yarns and fabrics the rule is relatively mechanical. For finished apparel, additional considerations like the garment's construction and the essential character analysis can come into play, but fiber predominance remains the starting point for most classifications.
When no fiber predominates
Blends like 50/50 cotton-polyester need the tie-break rules, and this is where the section notes earn their keep. The notes specify which fiber prevails in specific headings when weights are equal or when the product falls between categories. These are not judgment calls; they are lookup rules, and they must be applied exactly as written.
Multi-fiber blends with three or more components follow the same logic extended: rank by weight, apply the predominance rule, and use the notes for ties. A 40/35/25 blend classifies on the 40 percent fiber unless a specific note says otherwise for that product type.
The common error is stopping at the two biggest fibers and ignoring the rest. Minority fibers rarely change the classification, but they can matter for products near a threshold, and they always matter for the documentation. Record the full breakdown.
Where apparel brands go wrong
The marketing fiber trap is the classic: a brand sells a performance shirt as a merino product, classifies it as wool, and the lab test shows 55 percent polyester. The classification follows the 55 percent, and the duty difference between wool and synthetic apparel headings is significant. Market the merino; classify the polyester.
Coatings and treatments cause the second class of errors. A coated or laminated fabric may classify as a coated textile rather than by its base fiber, depending on the coating. Brands that classify the base fabric and ignore the finish get the heading wrong.
Trims and linings cause the third. A jacket's shell, lining, and filling can each point to different classifications, and the rules for which component governs depend on the garment type. Classifying the whole jacket on the shell fiber without checking the garment-specific notes is a gamble.
Getting it right systematically
Require lab-verified fiber content for every blended SKU before it is classified. Supplier declarations are a starting point, but production varies, and the classification liability sits with the importer. Test the top-volume SKUs at minimum, and any SKU near a classification threshold.
Build a classification file per SKU: the fiber breakdown, the section notes applied, the heading chosen, and the reasoning. When customs questions the classification, this file is the answer. When the product changes, update the file and re-verify.
For the ambiguous cases, which textiles produce constantly, get a binding ruling. The cost of a ruling is trivial next to the duty at stake on a wrong classification across thousands of units.
Does the care label fiber order determine classification?
No, though it is often a good hint since labels list fibers by descending weight. Classification follows the actual weight breakdown of the goods as imported. If the label and the lab disagree, the lab wins and the label needs fixing too.
How do elastane and spandex affect classification?
Small percentages of elastane rarely change the heading, since classification follows the predominant fiber. But elastane content can matter for specific product definitions and for the documentation. Record it accurately even when it does not change the outcome.
What about recycled fibers in blends?
Recycled content does not change the fiber-content analysis: recycled polyester is polyester for classification purposes. Sustainability claims live in marketing and compliance disclosures, not in the tariff classification.