Das Papier Science and Technology 6/2008 Ghosting is certainly the most irritating of known technical problems in heatset web offset printing. Depend- ing on the angle of the blanket cylinder, the printed image on one side of a page will appear on the other side as a print- ing error – a ghost image in effect. Fig. 1 shows four examples of ghosting during ongoing production. The name ghosting is very appropriate, not just because of the ghost-like reduc- tion in tonal values, but also because of the apparently random ghostly occur- rence of this effect.  Das Papier 2008–T56 Dr. Gerd Meder, Mohn media, Carl-Bertelsmann-Str. 161 M, 33311 Gütersloh, Germany Dr.-Ing. Wilhelm Busse, Verein ZELLCHEMING e.V., Emilstr. 21, 64283 Darmstadt, Germany Dipl.-Ing. Maik Coesfeld, Mohn media, Carl-Bertelsmann-Str. 161 M, 33311 Gütersloh, Germany Dr. Erich Frank, Flint Group Germany GmbH, Sieglestr. 25, 70469 Stuttgart, Germany Anne-Sopie Gombart, Sappi Netherlands Services B.V., Biesenweg 16, 6211 AA Maasticht, Netherlands Dr. Joop van Hesteren, Solco NV, Zwaluwbeek14, 9150 Kruibeke, Belgium Dr. Dirk Lawrenz, BASF Aktiengesellschaft, ED/PD – H 201, 67056 Ludwigshafen, Germany Dr. rer.nat. Christian Naydowski, Voith Paper Holding GmbH & Co. KG, St. Pöltener Str. 43, 89522 Heidenheim, Germany Peter Resch, Sappi Papier Holding GmbH, Brucker Str. 21, 8101 Gratkorn, Austria Dr. Joachim Schoelkopf, Omya Development AG, P.O. Box 32, 4665 Oftringen, Switzerland G. Meder, W. Busse, M. Coesfeld, E. Frank, A.-S. Gombart, J. van Hesteren, D. Lawrenz, C. Naydowski, P. Resch, and J. Schoelkopf Ghosting in Heatset Web Offset Printing Fig. 1: Four examples of ghosting. Example 1: Recycling matt-coated paper, 65 g/m 2 , Example 2: Woodpulp paper, white, glossy coated, illustration printing, 80 g/m 2 , Example 3: Wood-free paper, white, glossy coated, illustration printing, 100 g/m 2 , Example 4: Newspaper printing, matt, upgraded, 52 g/m 2