Gravure Printability Comparison of Laser & Electromechanically Engraved Cylinders
By Xiaoying Rong
The gravure printability of laser and electromechanically engraved cylinders was studied. Laser and electromechanically engraved cylinders were used to print on one packaging and four publication grade substrates with ink of the same viscosity. Print from laser-engraved cylinders showed that substrates’ properties have less influence compared with electromechanically engraved cylinders in terms of dot gain. The maximum dot gain of laser-engraved tones is 30 percent, compared to 50 percent on electromechanically engraving ones. Electrostatic assist has less effect on laser-engraved cylinders than electromechanically engraved cylinders. Dot-gain curves of laser-engraved cylinders are smoother than electromechanically engraved cylinders. This could help to improve the accuracy of gamma correction curves. It was found that laser-engraved cylinders with spherical cell shapes helped to improve print quality in terms of higher optical density, higher specular gloss, better tone reproduction, and lower mottle.