ASTM D7189-2012 (2020) specifies laboratory procedures for determining the relative hiding ratio of newsprint on newsprint for black oil-based newsprint and color newsprint by osmotic drying. The test method uses Proofer, Analytical Balance, and Reflection Density Meter to determine the amount of inks required to reach the target density by measuring Optical inspection density at different ink film weights. The method can also be used to evaluate the acceptability of newsprint to inks, help optimize ink usage efficiency, reduce printing costs, and is widely used in quality control and inks research and development in the press and publication industry