HTS code 4804.52.00 covers "Uncoated kraft paper and paperboard, in rolls or sheets, other than that of heading 4802 or 4803 › Bleached uniformly throughout the mass and of which more than 95 percent by weight of the total fiber content consists of wood fibers obtained by a chemical process" under the US Harmonized Tariff Schedule. This is the official duty rate charged by US Customs when this product is imported into the United States, sourced directly from the U.S. International Trade Commission and refreshed daily.