Subheading 320611 covers pigments and preparations containing 80% or more titanium dioxide by dry weight. Preparations with a lower TiO₂ content, or those formulated with significant additional components that bring the TiO₂ share below that threshold, fall under 320619. The dry-weight concentration of TiO₂ in the finished preparation is the controlling criterion.

Inorganic products used as luminophores are specifically provided for under 320650 within this heading. Organic luminophores, by contrast, fall under the synthetic organic coloring matter heading. The inorganic versus organic chemistry of the luminescent compound is the classification dividing line.