Pearl pigment is a flake material that produces pearl luster through physical optical effects, which has the characteristics of a composite structure composed of multiple layers of transparent or translucent media.
The color rendering principle of pearl pigment is based on the phenomenon of thin film interference. When the incident light reaches the surface of the pearlescent pigment, part of the light is reflected for the first time at the surface metal oxide, and the other part penetrates to the substrate interface for secondary reflection. The two beams of reflected light have a phase difference due to the path difference. When the optical path difference is equal to an integer multiple of a specific wavelength, constructive interference occurs, which increases the intensity of visible light of the corresponding wavelength, thereby presenting the main color at a specific observation angle. As the viewing angle changes, the effective optical path difference changes, and the dominant interference wavelength migrates accordingly, resulting in a continuous transition from blue-purple to red-gold.
The color rendering intensity of pearl pigment is affected by the optical properties of the substrate material. Using a high-reflectivity substrate can improve the utilization of light and increase the saturation of interference colors by about 40%; while a low-refractive-index substrate promotes multi-layer reflection and enhances the soft-focus effect of pearlescent light.
The use of multi-layer coating technology further expands the color rendering modulation ability of pearl pigment. This design allows the pigment to maintain a significant iridescence effect in a diffuse light environment, overcoming the dependence of traditional single-layer structures on direct light.
