Three-dimensional characterization of ink vehicle penetration by laser scanning confocal microscopy (2)
Publication Name: Journal of Pulp and Paper Science
The penetration of ink into paper influences the final product quality, ink usage and ink show-through. To quantify the penetration of the ink vehicle into the paper base sheet, cyan offset inks, stained with a fluorescent dye, were printed on two papers, each of which was tested on one side only. The location of the vehicle is measured with laser scanning confocal microscopy (LSCM). The penetration of the ink vehicle was observed by three-dimensional images. An oil-immersion objective lens could be utilized for the high-resolution observation of vehicle penetration. The differences in vehicle penetration by ink types and by surface sizings on paper could be characterized by this LSCM technique. In addition, simultaneous observation of the ink vehicle and paper was demonstrated using a double-staining technique and the sequential scan mode of LSCM. The ink vehicle was found to have a high concentration in regions of the paper that had high filler content.