Several types of ink pigments used for either printing opaque whites (called opaque pigment) or for tinting, extending, or reducing the strength of other color pigments (called transparent pigment). Commonly used white pigments include Zinc White, Titanium Dioxide, Zinc Sulfide, Lithopone, Alumina Hydrate, Calcium Carbonate, Blanc Fixe, Barytes, talc, silica, and China Clay.
The white pigments listed above are classified and identified in the Society of Dyers and Colorists' Color Index. Each classification consists of two parts, corresponding to the two parts of the Index: The first part identifies each pigment with a CI number, which accompanies a description, usage, and technical information. The second part lists each pigment by chemical composition, and assigns each one a single number. Thus, calcium carbonate above is listed in Part 1 as CI Pigment White 18 and in Part 2 as No. 77220. These two sets of identifications accompany the individual entries for each separate pigment.