4805.91 - Weighing 150 g/m² or less:

This category, HTS 4805.91, encompasses "other uncoated paper and paperboard" that weighs 150 grams per square meter (g/m²) or less. It falls under the broader heading of paper and paperboard not further worked than specified in Chapter 48's note 3. This specifically includes various types of paper and paperboard not readily classifiable under more specific subheadings within Chapter 48, provided they meet the weight criteria and are uncoated.

The primary distinguishing factor for HTS 4805.91, when compared to its sibling categories 4805.92 and 4805.93, is its weight. While this category is limited to papers and paperboards weighing 150 g/m² or less, 4805.92 covers those weighing between 150 g/m² and 225 g/m², and 4805.93 includes those weighing 225 g/m² or more. This weight specification is a critical criterion for accurate classification.

Within HTS 4805.91, further subdivisions exist to account for specific types of paper and paperboard. These include multi-ply papers and paperboards, as well as bibulous and wrapping papers under 4805.91.10. Additionally, condenser paper, a specialized type used in electrical capacitors, is classified under 4805.91.20.00. The "Other" subcategory serves as a residual classification for items meeting the general description of 4805.91 but not fitting into the more specific subheadings.