Colorimetric Parameters of Lithographic Prints at Various Film Thicknesses

The International Standards Organization (ISO) has a committee attempting to set international colorimetric standards for printed ink films. To accomplish this task, prints of representative ink sets from three areas of the world have been printed onto a standard paper at a range of film thicknesses. A laboratory method for printing offset inks has been developed and was used to prepare these prints. The resulting prints have been measured on spectrophotometers of two different geometries and the resulting colorimetric data calculated. A technique has been devised for cross-plotting the color parameters versus film thickness, which should allow ink manufacturers to more easily formulate process ink sets which will meet the proposed standards. Examples of such plots are given here.