Kaolin extends titanium dioxide, controls sheen, and improves film durability. A practical look at why formulators rely on the right clay grade.
The economics of extender pigments
Titanium dioxide is the most expensive component in most paint formulations. Kaolin acts as an extender pigment that spaces TiO₂ particles efficiently, maintaining opacity and hiding power while reducing the amount of costly pigment required.
Sheen and film properties
Calcined and hydrous kaolins let formulators dial in matte to eggshell finishes, control gloss, and improve scrub resistance. The clay also reinforces the paint film, contributing to durability and crack resistance over time.
Rheology and application
Kaolin influences how a paint flows, levels, and settles in the can. A well-controlled grade improves suspension of other solids and delivers smooth application without sagging or brush marks.
Choosing a paint-grade clay
Formulators should specify brightness, oil absorption, and particle size, and confirm low grit and consistent supply. A paint-grade kaolin from a direct manufacturer keeps colour and finish uniform across production runs.
