Method for improving the optical properties of paper

摘要

Optical properties of paper may be improved by using as a filler a form of calcium carbonate having a blocky-six-sided rhombohedral final crystal morphology, with a surface area of from about 3 to about 15 m²/g, an average discrete particle size of from about 0.2 to about 0.9 microns, wherein the discrete particles have an aspect ratio less than 2, and a particle size distribution such that at least about 60 weight percent of the particle lies within 50 percent of the equivalent discrete particle spherical diameter.