4804.31 - Unbleached:

This HTS category, 4804.31, specifically covers unbleached kraft paper and paperboard that weighs 150 grams per square meter or less. These materials are characterized by their natural, unbleached appearance, indicating the absence of bleaching agents to achieve a white finish. Kraft paper is known for its strength and durability, derived from the kraft pulping process. This classification is applicable to both rolls and sheets, excluding those specifically classified under headings 4802 (uncoated paper and paperboard, 150 g/m² or less, machine-made, for writing, printing, or other graphic purposes) and 4803 (toilet paper, tissues, etc.).

Within the broader context of "Other kraft paper and paperboard weighing 150 g/m² or less," this subcategory distinguishes itself from its sibling, 4804.39, by its unbleached nature. The sibling category, 4804.39, would encompass kraft paper and paperboard in the same weight range that are either bleached or otherwise treated, which are not specifically covered by other headings.

The subcategories of 4804.31, namely 4804.31.40 (wrapping paper) and 4804.31.60.00 (other), further refine the classification based on the intended end-use or specific product type. "Condenser paper," for instance, would fall under the "other" designation unless it specifically meets the criteria for wrapping paper. These subdivisions allow for more precise tariff application, recognizing that even within the broad definition of unbleached kraft paper, distinct applications may warrant separate classification.