The vehicle or carrier system—oil-based, water-based, or solvent-based—is a primary classification driver under the HTS. Inks may fall under different headings depending on whether the colorant is a pigment or dye and the intended printing process, so a binding ruling from CBP is advisable when the formulation is ambiguous.

Many printing ink formulations originating in China are subject to Section 301 tariffs. Importers should verify the specific 10-digit HTS classification of their product against the current Section 301 annexes, as coverage and rates vary by ink type and chemical composition.