Artificial staple fibers (viscose rayon, modal, lyocell, cupro) are derived from cellulose and classified in heading 5516, while synthetic staple fibers (polyester, nylon, acrylic) are petroleum-based polymers classified in headings 5512–5515. Fiber content test reports or supplier mill certificates identifying the fiber type are the standard documentation used to support the classification.

Because the viscose rayon content is under 85% and the fabric is mixed mainly with cotton, the applicable subgroup is the cotton-blend series (551641–551644). The specific subheading then depends on finishing state: 551641 for unbleached or bleached, 551642 for dyed, 551643 for yarn-dyed (different colored yarns), and 551644 for printed.