4805.24 - Weighing 150 g/m² or less:

This HTS classification (4805.24) pertains to testliner, a type of paperboard primarily produced from recycled fibers. It is specifically characterized by a basis weight of 150 grams per square meter (g/m²) or less. Testliner, in this context, is considered "other uncoated paper and paperboard" and has not undergone further working or processing beyond what is outlined in Note 3 to Chapter 48. Its primary application is often as a facing layer in the production of corrugated board, providing a printable surface and contributing to the structural integrity of the final packaging material.

The key differentiator for this category, 4805.24, lies in its defined weight range. It is distinguished from its sibling category, 4805.25, which covers testliner weighing *more* than 150 g/m². Therefore, the precise weight measurement is crucial for correct classification.

Within 4805.24, further subcategories exist to refine the classification based on even finer weight distinctions. These subcategories (4805.24.50, 4805.24.70, and 4805.24.90) allow for a more granular breakdown based on whether the testliner weighs not over 15 g/m², over 15 g/m² but not over 30 g/m², or over 30 g/m², respectively. This detailed breakdown ensures that the specific grade and intended use of the testliner can be accurately identified for customs purposes.