| Function | An example of a morphological attribute |
| Increase paper density | plate-like (clay) |
| Increase paper thickness | larger, three-dimensional filler particles |
| Improve light scattering/opacity | particles with internal voids |
| blocky rhombohedral (0.4 - 0.5 µm) | |
| rosette-shaped (0.9 to 1.5 µm) | |
| Maintain paper stiffness | large-size scalenohedral |
| Improve dewatering | rounded, solid-form particles |
| Maintain strength (at high % filler) | clustered prismatic structure |