IMAGE ANALYSIS OF AN LWC PAPER REVEALS WIRE MARK IN THE PRINT DENSITY VARIATIONS.

Microscopic observations were combined with image analysis to study the causes of apparently random 'speckles' and 'blotches' in a lightweight coated publication paper printed on a four-color web offset press. The speckles were areas of lower print density lying over areas of greater coating thickness. Much of the higher frequency variation in print density corresponded exactly with the forming fabric pattern. Thus, some of the small-scale print nonuniformities often attributed to the coating process itself are actually caused by the basesheet.