Effect Pigments, UL Prospector, Ronald Lewarchik, 5/2016: Effect pigments provide an infinite array of colors and effects that enable unlimited design possibilities for coatings. These effects include the illusion of flickering lights, metallic reflection, interference sparkle and color variation and luster that changes with the viewing angle and light source.
They are used in a variety of coatings, including those in automotive, monumental and smaller buildings as well as other industrial and product finishing applications. Pigments may be broadly classified by their ability to reflect light: absorption, metallic and interference.
Conventional organic and inorganic pigments are classified as absorption pigments, because they absorb certain wavelengths of the incident light that strikes their surface. The sensation of color is produced by the remaining component of the reflected visible light that produces the color we observe.
For example, a quinacridone red pigment reflects the portion of the light that produces a red color and absorbs the rest of the light energy. Titanium dioxide reflects all of the light and absorbs none, while carbon black absorbs all and reflects none. Due to their ability to absorb light, absorption pigments do not display a metallic luster or iridescence and are thus one dimensional in their ability to interact with light.
Metallic pigments consist of tiny flat pieces of aluminum, bronze, zinc, copper, silver or other metals that reflect light and thus create a metallic luster. These pigments are two- dimensional or metallic pigments.
Effect pigments are unique in respect to how they interact with light due to their geometry which is normally a platelet with a high aspect ratio (ratio of width to height). Depending upon the specific technology, a wide variety of colors and effects can be created, such as interference shimmers, color travel effects or metallic reflection.
To read the rest of Ron’s article, click here to head over to UL Prospector.