For the US market, a label that names the fibres without percentages is not the usual way to comply. The rules under the Textile Fiber Products Identification Act, set out in 16 CFR Part 303, require the fibre content to be disclosed by generic fibre name and percentage by weight, in order of predominance. Your label should state the percentages, for example "96% Cotton, 4% Spandex". Confirm the final wording against the regulation or with your compliance adviser.

The under-5% rule and its exception

Part 303 generally requires fibres present at less than 5% to be shown as "other fiber" or "other fibers" rather than by name. There are exceptions where a small amount of a fibre has a clearly established functional significance, and elastomeric fibres such as spandex are the typical example in apparel. Their stretch is the reason they are in the garment. Read the relevant section of Part 303 for the exact conditions, because whether you may name a small percentage depends on that functional significance.

Generic names, not trade names alone

The rules use generic fibre names. The FTC's 2014 amendments to the Textile Rules also updated the incorporated ISO 2076 standard for generic names. In the US, "spandex" is the generic name; "elastane" is the ISO name. Part 303 has provisions on using ISO names, so check which form you intend to use. A trademark name can appear alongside the generic name but should not replace it.

Other required information

Fibre content is only part of the label. Part 303 also covers country of origin and the identity of the manufacturer or dealer, which can be a name or an RN number. It also covers where labels must appear; for garments with a neck, origin is expected at the inside centre of the neck. Care instructions fall under a separate rule, the FTC Care Labeling Rule. Plan the label artwork with all of these at once so you print it only once.

Keep the label tied to the fabric

Base the percentages on the fabric supplier's composition data for the bulk fabric, not on the development swatch. If the blend changes between sample and bulk, the label must change too.