False color plots of crystal grains in polycrystalline Al. The three-dimensional picture shows the volume of polycrystalline Al investigated with polychromatic 3DXM. The three slices below are false color plots of the grain sizes on a particular slice of the three-dimensional volume after isochronal annealing at 623, 628 and 633 K for 1 h between measurements. Adapted from Budai et al. (2008) with permission.