AbstractPrint non‐uniformity is a major concern for flexo post‐printers. Many of these non‐uniformities are suspected to be caused by the corrugated board structure itself. Striping is the most obvious one, but also other print quality problems might be structure‐related. This work focuses on how deformations of the board might lead to print non‐uniformities, and if the deformation of halftone dots is the mechanism behind striping in halftone flexo post‐printing. Finite element models were used to analyse the effects of deformations of corrugated boards and compressed halftone dots in the printing nip. Distortions of the board due to non‐uniform hygro‐thermal strains were shown to be a potential cause of print non‐uniformities. Striping in halftone prints was found to be caused by differences in dot gain between areas above ridges and valleys of the flute structure. Copyright © 2008 John Wiley & Sons, Ltd.