Carded wool (heading 5105, subheading 510510) retains short fibers and produces a bulkier, softer yarn suited to woolen-system fabrics like tweeds, blankets, and felt. Combed wool tops (subheadings 510521 and 510529) have had short fibers removed, yielding a smoother, stronger worsted yarn used in fine suiting and hosiery. The choice between them drives both the classification and the downstream mill process.

The Wool Products Labeling Act (WPLA) requires that wool content be accurately disclosed on finished consumer products, but the labeling obligation attaches to the finished article rather than the raw fiber import. However, importers of carded wool should maintain supplier documentation — including fiber type, grade, and any recycled-fiber content — to support downstream compliance when the fiber is incorporated into labeled consumer goods.