FUNDAMENTAL COLOR MEASUREMENTS IN THE GRAPHIC ARTS

Measurements of (transparent) colored inks on paper made precisely in accordance with standard recommendations will include both the ink color and the paper color. These combination measurements, while sometimes informative, may cause confusion in interpretation of results. Measurements that use a black backing sheet also incorporate the opacity (translucency) of the paper in the result. This paper will show how paper color, ink color, and opacity can be separated for a more complete understanding and for better control of process color printing. Spectrophotometric measurements are made and recorded in accordance with CIE and ASTM recommendations. Subsequent calculations from spectral data may be made with the paper included or excluded.