Opacilite™ is a high whiteness “flash calcined” kaolin produced by a revolutionary new rapid heating process. This patented technique creates large numbers of intrinsically sealed voids within the clay particles. These tiny voids provide outstanding opacifying properties in coatings below and above the critical pigment volume concentration (CPVC), specifically less than 65% PVC. In addition, the low specific gravity provides an inherent volume cost saving. The presence of these sealed voids distinguishes Opacilite from conventional mineral extenders. Opacilite also has external voids on its surface, which contribute to opacity above CPVC.