Print Quality of Linerboard in Commercial Water-based Flexography.

Seventeen North American linerboards -- brown, white-top, and solid bleached kraft -- were printed on a commercial web flexo press with water-based inks. Press variables included ink viscosity, plate hardness, and printing pressure. The quality of a halftone photograph increased as the board became smoother and brighter, and also increased with a harder printing plate and a higher viscosity ink. Contrary to conventional wisdom which states that bar codes printed on very dark or rough linerboards are more difficult to read, readablity was independent of linerboard brightness and roughness. However, bar code readability was poorer on more water-repellent boards, or with inappropriate printing pressures (whether too high or too low). Across the sample range solid print density and ink holdout decreased as the liners became rougher and more water-repellent. However, within each grade there was no correlation between print density, roughness, and surface chemistry.