A fluting paper is NESOI under 480519 when it is neither produced by the semichemical process from wood pulp (480511) nor made primarily from straw fiber (480512). Examples include corrugating media made from recycled fiber by processes other than those covered by the testliner subheadings, or from non-wood, non-straw annual plants. The classification requires a process-of-manufacture analysis, and importers should obtain mill documentation confirming the pulping method and fiber source.

Both countries have domestic paper industries that produce specialty or recycled-fiber corrugating media, sometimes from non-traditional fiber sources. Niche grades or specific basis weights not readily available from North American or major European mills can drive sourcing from less conventional origins. Supply-chain diversification and specific technical specifications are the most common reasons US buyers look beyond Canada for this product.