Some Insight into the Relevance of Off-press Measurements of Fountain Solution Takeup by Ink

A printing problem of excessive blanket piling in the image areas on a web press was investigated by conducting off-press measurements of fountain solution taken up by ink. The ink-fountain solution combinations tested included those that performed badly and those that eliminated the problem. Three different type measurement were made. The first originally suggested by Surland, utilized a Duke tester, while the second utilizing a litho break tester, was one suggested by Tasker, et al. The third, observing the effect of mixing some of the combinations in a laboratory ultrasonic cleaner, was suggested by Blom. Data is presented to show to what extent the three types of measurements correlate with each other and with the on-press problem of excessive image area piling. The data is also analyzed to determine whether ink or fountain solution was the controlling factor vis-e-vis the problem encountered.