Metallic Effects - More Than Just Colors

Color exults and arouses emotions.

In recent years, there has been an increase in preference for colors with a metallic finish. The car industry understands this trend and uses metallic pigments to enhance appearance and quality of surfaces.

Conventional pigments interacts with light by absorption and scattering. Metallic pigments consists of small metallic flakes which acts like small mirrors to reflect light.

When light strikes a metallic color surface
- specular light is reflected in the opposite direction by the top coat
- light is scattered by pigments
- light is reflected by flakes

Metallic paint with low transparent pigments scatter some of the brightness to other viewing angles and the brightness of the paint does not change much when viewing angles change. This color is described as having low flop.


Metallic paint with high transparent pigments absorb light, reducing the amount reflected outward and when viewing in the specular angle, the brightness is highest than when viewed from other angles, the brightness decrease rapidly. This color is described as high flop.

Solid colors does not exhibit flop as the pigments scatters the light.

Brilliance or glitter is one of the desired feature of metallic colors. This characteristic is influenced by the distribution of metallic flakes. Flop index expresses the distribution characteristic of metal flakes.

Flop Index = L*Highlight / L*Shade

When flakes are poorly oriented, there is little effect in coating appearance as viewing angle is changed. To achieve a desired flop, the flakes must oriented in a desired pattern within the coating. Techniques to improve orientation includes selecting the right pigment, maximising the film shrinkage and using the right additives to enhance flake orientation.