In previous "Formulating with Mike" articles, I covered pigment additives such as dispersants, surface tension modifiers and control agents. This month I will discuss how light and pigment interactions affect hiding, tint strength and other properties of a coating. Stay tuned, as later in this series, we will go into depth on the pigment dispersion process.
Pigments, unlike dyes, are finely ground insoluble particles, and pigments are used in most coatings because they provide critical properties for the intended application. The pigments used depend upon the specific application. Pigments are divided into three main types: primary, extender and specialty.