Defining the Optical Hiding Power of Printing Papers and Printing Inks

KCL needed a system that can be used to assess the optical hiding power of colored printing papers and printing inks. Colored prints did not have a measurement standard that would define the optical hiding power of printing papers and printing inks sufficiently well. Optical hiding power refers to the opacity of paper, which is a significant factor when printing text or images on both sides of the paper.

To define the optical hiding power of colored prints, the InFotonics Center Joensuu developed a system which combines a commercial color scanner with a piece of software that utilizes a completely new computational method. The system makes it possible to define the number of different colors that can be printed on different papers without them showing through and disturbing the reader. The work involved, among other things, visual tests in which test subjects were asked to assess how different colored papers and printing inks affect the optical hiding power.

KCL utilizes the system in its R&D activities for defining the optical hiding power of colored prints.

Research Collaboration with the InFotonics Center Joensuu: KCL serves the global paper and forest cluster industries as well as the end-users of paper and board products. For more information on the company, see: www.kcl.fi.