Improving the Pre-Inking of an Offset Press by Checking some Simple Paper Properties

In order to optimize ink mileage, Heidelberg Web Systems and EFPG carried out a joint research project. The aim of this study was to find the relevant paper properties that allowed a finer setting of the ink keys, thanks to the Densicontrol(r) system. Tests were conducted on a panel of web offset papers and inks. Emphasis was put on the following properties : - paper roughness, porosity and printability; - viscosity, tack and viscoelasticity of the inks. Since a good correlation was found between paper roughness and the settings of the Densicontrol(r), this approach was applied to sheetfed consumables, without the use of any pre-inking device.