Plate-Like Pigments in Automotive Paints: a Review
Second, if the plate-like particles are based on, or contain, selectively absorbing materials the interaction with light is based on absorption and reflection. As a result, both the reflected and the transmitted light are colored. Plate-like iron oxides (e.g., BASF Paliocrom Copper L 3000 and L3101) and plate-like phthalocyanine (BASF Paliochrom Blue Gold L 5000) belong to this group.
The solution is to strengthen the reflection - and thus the chroma - by surrounding the non-absorbing dielectric with a very thin semi-transparent layer of highly reflective material.