The 36 cm minimum width is a hard boundary in the SITC and corresponding HTS schedules. Rolls at or below that width are classified under different headings, potentially attracting different duty rates. Importers should verify roll width at the point of manufacture and document it on commercial invoices to avoid misclassification.

Both fiber types fall within SITC 64163, but buyers in regulated markets may require chain-of-custody certifications (such as FSC or SFI) for virgin-fiber stock, and recycled-content declarations for post-consumer grades. These are commercial and sustainability requirements rather than US customs mandates, but they are increasingly standard in procurement contracts.