Surface micro-distributions of pigment and the relation between smearing and local mass distribution

In this work, the process of smearing and its time evolution have been inve stigated. When smearing occurs, the print is removed from the printed paper and colours other parts of the paper or the printing press and destroys th e final product, To study the re-distribution of ink, cyan ink with Cu as a tracer in the coloured pigment has been used. Non-printed paper has been p ressed against the paper, I and 5 s after the printing. The micro-distribut ions of ink on both printed and non-printed papers have then been studied u sing particle-induced X-ray emission (PIXE). Basis weight was measured with the off-axis scanning transmission ion microscopy (STIM) technique and thi s data was correlated with the data from the print. One conclusion is that the process of smearing is not dependent on the shape of the pigment distri bution, i.e. copper, or the content of copper in a specific pixel. On the c ontrary, the smearing was found to be related to the structure of the paper and that it mainly occurs where the paper is thicker. (C) 2001 Elsevier Sc ience B.V. All rights reserved.