Kraftliner is designed for use as the facing layer of corrugated board and is characterized by high tensile and burst strength at relatively high basis weights. Sack kraft paper is engineered for multiwall bag construction — it is typically lighter, more extensible, and porous enough to allow air escape during filling. The intended end use and physical properties (extensibility, porosity, weight) are the practical differentiators.

The 95% chemical wood fiber threshold in subheadings 480442 and 480452 distinguishes premium bleached kraft paperboard — used in food-service, pharmaceutical, and high-end packaging applications where fiber purity matters — from bleached boards with a higher proportion of mechanical or recycled fiber. Boards not meeting that threshold fall into the NESOI subheadings (480449, 480459). Mill certificates documenting fiber composition are the standard documentation for this distinction.