For years, color coatings manufacturers have been using high-shear mixing techniques to try to wet pigments and reduce particle sizes in raw materials before wet milling. The theory is clear. The smaller the bead you can use in the final milling process, the less mass-specific energy is required to create a quality color dispersion. And that means less energy cost for production, and less time to create a quality product.
However, the optimum bead size in wet milling is dictated by the largest particle size in the raw materials. Even small fractions of oversized particles left in the raw material after a pre-milling process will result in inefficient wet milling.