Woven Fabrics, 85% or More Nylon or Polyamide Filament, Unbleached or Bleached

The 85% threshold is measured by weight of all fibers in the fabric. A fiber composition test per AATCC or ISO methods is the standard verification approach. Elastomeric fibers like spandex are included in the total weight calculation, so even small percentages of spandex can push nylon content below 85% and shift classification to a different subheading. Importers should request certified fiber analysis from the mill before entry.

Typewriter ribbon fabric (5407410010 and 5407410020) is a historically distinct end-use product with specific weave density and width characteristics that CBP has long tracked separately for statistical and duty purposes. Although typewriter use has declined, the tariff lines remain active and can apply to similar narrow woven nylon fabrics used in printer ribbons or other precision ink-transfer applications. Correct classification requires confirming both the fiber content and the intended end-use.