The most important physical properties are:
Density 5-7 g/cm3
Mean particle size 0.4-0.8 pm
Specific surface area 12-4 m2/g
Oil absorption 30-10 g/100 g pigment
Compared with organic pigments, the density and particle size are relatively high while the specific surface area and oil absorption are quite low. This means very high pigment loading is possible. However, precautions must be taken to prevent sedimentation in low-viscosity systems, due to the high density of the particles and the fact that they readily settle out.
2.4.3