Correct Understanding And Widespread Use Of White Or Concealed Pigments

Pigments that provide light scattering properties for coatings are often referred to as white or hidden pigments. Due to their relatively high refractive index, they work by scattering light of all wavelengths, making them perceived as white by the human eye. They are called hidden pigments because the scattering of light reduces the likelihood of light passing through the colored film to reach the substrate. The coating of light scattering pigments with sufficient thickness and concentration is actually opaque, covering the substrate. The whiteness and opacity brought by this type of pigment make it one of the widely used pigments in coatings.

The widely used white pigment is titanium dioxide (TiO₂), which is called rutile. In any material that can be manufactured as a pigment at a reasonable cost, rutile has a high refractive index (2.76), making it an effective white pigment. The other crystal is TiO₂. anatase is sometimes used in coatings, but its low refractive index (2.55) makes its optical efficiency low.

In addition, TiO₂ surface treated in the form of rutile produces coatings that are more resistant to external exposure than equivalent anatase pigments. TiO₂ pigments are widely used worldwide, especially in so-called trade sales markets, including retail, construction, and contractor markets. In these applications, light, pastel, and white coatings dominate, thus requiring TiO₂.