Sample preparation Beech wood (Fagus sylvatica) was obtained from a local supplier of firewood in Magdeburg (Germany). The logs were dried according to industry standards without any further modification. X-ray micro-computed tomography (µ-CT) The microstructure was captured using a TESCAN UniTOM HR X-ray μ-CT device (Tescan Group a.s., Czech Republic). Image acquisation parameters were as follows: Voltage: 90 kV Emission current: 234.5 μA Number of projections: 4391 Image processing The image processing followed: Anisotropic diffusion filtering with 10 iterations Global thresholding with an intensity value of 0.5 Removal of all holes in the solid Data files The dataset includes 2 files, which are as follows: img@raw_res@1050x1050x1050_vxl@1.124997x1.124997x1.124997_uint16.raw.zip:Contents: Unprocessed image data of the microstructureResolution: 1050 × 1050 × 1050Voxel size: 1.124997 µm (in each dimension)Encoding: uint16 img@binarized_res@1050x1050x1050_vxl@1.124997x1.124997x1.124997_uint8.raw.zip:Contents: Binarized version of the previous raw imageResolution: 1050 × 1050 × 1050Voxel size: 1.124997 µm (in each dimension)Encoding: uint8Interpretation: 0 = void, 1 = solid