Methods combining micro scale resolution x-ray shadow graphs, computerised x-ray micro-tomography and advanced image analysis were developed to study connections between the structure of void space and raw edge imbibition in liquid packaging board. Imbibition roughening was analyzed from 2D shadow graphs by a dynamic interface recognition algorithm. An idea of investigating flow paths in cardboard samples using potassium iodine in water solution as contrast enhancement substance was introduced. For demonstrating the potential of the tomographic methods, numerical lattice Boltzmann permeability simulations were performed. Experimental measurements were conducted to compare and support the results extracted from tomographic data. A 3D void space segmentation algorithm was utilized to analyze structure of void space in tomographic reconstructions. Tentative results indicate that the new methods can be used to find correlation between pore size heterogeneity and imbibition roughening. Finally, water absorption coefficients of the test samples were calculated utilizing results extracted from the void space segmentation analysis.