1. Forest Pilot Center Oy, FI-21200 Raisio, Finland, VTT Technical Research Centre of Finland, P. O. Box 1199, FI-70211 Kuopio, Finland, School of Science and Technology, Faculty of Chemistry and Materials Sciences, Department of Forest Products Technology, Aalto University, P. O. Box 16300, 00076 Aalto, Finland, and Research and Development, Omya Development AG, CH-4665 Oftringen, Switzerland