Bleached Clay-Coated Kraft Paper & Paperboard, Over 95% Chemical Wood Fiber, Not Over 150 g/m²

Both are bleached clay-coated kraft paperboard under 150 g/m², but the US schedule assigns them to separate 10-digit lines: folding carton stock to 4810311020 and base stock for trays and similar items to 4810311040. The distinction is based on the declared end use and the board's structural specifications. Importers should document the intended converting application and confirm the correct line with their customs broker, as misclassification between these lines can affect duty liability.

Yes — heading 481031 requires that more than 95% of the fiber content derive from chemical wood pulp processes (kraft or sulfite). Boards with a significant mechanical or recycled fiber component would not meet this threshold and would classify elsewhere. Mill fiber-composition certificates are the standard supporting document for verifying this criterion at entry.