The manmade fiber component must be the predominant non-cotton fiber by weight — meaning the fabric's non-cotton content consists mainly of synthetic or artificial fibers such as polyester, nylon, or viscose. If the fabric is instead blended mainly with wool, linen, or another natural fiber, it falls under heading 5212 rather than 5210.

Because the cotton content is below 85%, it cannot enter heading 5208 (which requires 85% or more cotton). If the polyester is the primary non-cotton fiber and the fabric weighs 200 g/m² or less, heading 5210 is correct. Confirm the fiber percentages by weight through laboratory analysis before filing.