Delamination of multiply paperboard during offset printing is caused by the ink tack induced forces applied on the surface of the board. The purpose of this investigation was to analyze the influence of mechanical properties of the plies and interface resistance on the delamination behaviour of the paperboard. Paperboard was modelled as a four-ply sandwich structure. A user-defined interface model described the mechanical behaviour of the interfaces between the plies. The results in terms of critical ink tack length and stress conditions in the interfaces at delamination initiation were defined for different ply structures. The delamination process in multiply paperboard was highly dependent on the stress concentration caused by the ink tack. The delamination always occurred in the interface between top and middle ply. The main stress component causing delamination was tensile stress in the thickness direction, whereas the interlaminar shear was less relevant. Bending stiffness and in-plane tensile stiffness influenced the critical ink tack length, but did not affect the stress situation at the delamination point.