**2.1 Tomography imaging of porous samples**

Authentic simulation geometries were obtained by utilising CXµT. Both synchrotron -based x-ray beams and conventional x-ray tubes were used as the radiation sources. The adequate resolution and the overall quality of the images depend on the techniques used. In this study, two laboratory scale devices (Sky-Scan 1172 and Xradia Micro XCT-400) based on xray tubes, and a tomographic imaging facility ID19 of the European Synchrotron Radiation Facility (ESRF) were used.

The voxel resolution of the laboratory scale devices can be varied from a few micrometres up to few tens of micrometres. The wool fibre web sample was imaged by SkyScan 1172 device with the voxel resolution of 4.48 µm and the sand stone sample with Xradia Micro XCT-400 with the voxel resolution of 2.10 µm. The packaging board sample was scanned at ESRF beam-line ID19. The imaging set-up used at ID19 facility had the voxel resolution fixed to 0.7 µm.
