Fine animal hair for trade classification purposes generally includes fibers from animals such as cashmere goats, angora rabbits, camels, alpacas, and similar species, with defined maximum fiber diameter thresholds. Wool from sheep is classified separately. If a tufted rug contains a blend, the predominant fiber by weight typically governs classification, making laboratory fiber analysis reports an important part of import documentation.

Tufted rugs are produced by inserting yarn through a backing fabric using needles, then applying a secondary backing — a faster, more industrial process than weaving. Woven wool rugs are constructed on a loom with interlaced warp and weft. The distinction matters because the two construction methods fall under different SITC and HTS classifications, potentially carrying different duty rates, and because buyers in the contract and residential markets often specify construction type for performance and aesthetic reasons.