Flute type (A through F) determines cushioning, stacking strength, and printability: A-flute offers maximum cushioning, while E and F flutes provide a smoother surface for high-quality printing. Double- and triple-wall constructions multiply compression strength for heavy industrial loads. These structural choices affect both the box's performance certification and, in some cases, its HTS classification, so specifications should be confirmed before import.

Yes — certain corrugated and fiber box imports from China have been subject to Section 301 tariffs. The applicable tariff list and product scope should be verified against current USTR guidance, as product exclusions and list modifications have occurred over time. Importers should work with a licensed customs broker to confirm current duty exposure for their specific HTS classification.