Kaolin clay pigments suited to rotogravure printing applications and method for preparing the same

The present invention relates to improved kaolin clay products suitable for use in rotogravure printing processes, for coating lightweight and ultra lightweight paper for rotogravure and offset printing, and to methods for making the same. The present invention provides kaolin clay pigments having at least the following characteristics: Brightness (GE): at least about 89.0; Shape Factor: at least about 30; Brookfield viscosity, measured at 20 rpm and at less than or equal to about 65% solids: about 100 to about 700 centipoise; and Hercules viscosity, measured at 18 dynes and at less than or equal to about 65% solids: about 200 rpm to about 1000 rpm. Preferred kaolin sources include Brazilian kaolins, especially Rio Capim kaolins. The kaolin pigments of the present invention possess a combination of optical and physical properties, such as brightness, printability, and transfer efficiency, not previously seen in existing commercial products. They are useful, e.g., in paper filler and coating compositions, ink compositions, and printing applications, especially rotogravure printing.