4106.31.10.00 - Wet blues

This HTS classification, 4106.31.10.00, specifically covers "wet blues" derived from the hides and skins of swine. Wet blues represent a crucial intermediate stage in leather processing. They are characterized by being treated with chromium salts, which preserves the skins, imparts a characteristic bluish hue, and prevents putrefaction. At this stage, the skins are still moist and have not undergone further tanning processes like vegetable tanning or finishing.

This category is distinct from its sibling, 4106.31.90.00, which covers "other" tanned or crust skins of swine that are not in the wet state. While both fall under swine skins and are prepared but not further processed, this specific category is reserved for those skins that are still in a preserved, moist, chromium-tanned condition (wet-blue), prior to reaching a more finished or dry state. The distinction is critical for import/export declarations, reflecting the material's specific stage of production and handling.

As this is a leaf node within the HTS structure, there are no further subcategories. The classification is definitively applied to swine hides and skins that meet the criteria of being in the wet-blue state. Practical classification relies on identifying the presence of chromium tanning salts and the moist condition of the material, differentiating it from dried crusts or fully tanned leathers of swine origin.