Details:
Summary:
Metallic inks have long been used to enhance the value and convey quality of the printed piece. As with any ink, it is necessary to measure the optical density of the ink with a densitometer or spectrodensitometer to ensure correct color and print quality. It had been determined that densitometer readings fw metallic inks among several instruments out on the market did not correlate well if the ink film thicknesses were varied. Understanding the correct readings help in preventing set off in the stack, insufficient drying of ink in web presses, better control of ink and water balance, and yield more consistent results between printed pieces. This study suggests that the employment of a polarized light filter in a reflection based densitometer or spectrodensitometer provides a better representation for comparing e c a l density values to ink film thicknesses than those instruments without such filters. Comparative test results of different makes of densitometers with and without polarized filters are discussed and shown via various graphic charts and pictures.