Classification depends on which material gives the article its essential character. If the plastic component predominates and the textile is merely a backing or reinforcement, the article typically falls under 392190 of heading 3921. If the textile gives the article its essential character, a textile heading may apply. The Section XI and Section VII notes, along with GRI 3, govern the analysis, and a binding ruling is advisable for ambiguous laminates.

Both EPS and XPS are cellular polystyrene and fall under subheading 392111. The manufacturing process (bead expansion versus extrusion) does not create a separate tariff line within this heading; the resin type (polystyrene) and cellular structure are the controlling factors. Differences in density, compressive strength, or surface finish are commercially significant but do not alter the HTS classification at the six-digit level.