3204.15.10.00 - Vat blue 1 (synthetic indigo),"Colour Index No. 73000"

This HTS category, 3204.15.10.00, specifically classifies "Vat blue 1 (synthetic indigo)," also identified by its Colour Index Number 73000. This designation falls under the broader heading of vat dyes, which are characterized by their ability to be reduced to a soluble leuco form for application to textile fibers and then oxidized back to their insoluble pigmentary state. Synthetic indigo is a prime example of this class of dyes, widely recognized for its historical significance and persistent use in coloring textiles, particularly denim.

Distinguishing this specific code from its sibling categories is crucial for accurate classification. While other entries within 3204.15 cover a range of vat dyes and their preparations, such as "Vat brown 3; Vat orange 2, 7; and Vat violet 9, 13" (3204.15.20.00) or various "Solubilized vat" and other numbered vat dyes, this code is singularly focused on synthetic indigo. The presence of a unique Colour Index Number provides a definitive identifier, setting it apart from broader or differently specified vat dyes.

As this is a leaf node in the HTS classification structure, there are no further subcategories. Therefore, the focus remains on the precise identification and scope of synthetic indigo. This classification implies that any preparation or formulation primarily based on synthetic indigo, as defined by its Colour Index Number 73000, would fall under this heading, provided it meets the general criteria for vat dyes outlined in Chapter 32. The "Other" category at this level would serve to capture any vat dyes not explicitly listed in the preceding sibling codes, reinforcing the specificity of each listed item.