Fig. 7
From: Shrinkage and mechanical properties of drying oil paints
X-ray microtomographs of pictorial layer in a historic panel painting; cross-sections parallel to the surface: a paint layer, b ground. For presentation, the X-ray absorbing material is represented on a grey scale in which white and black colours correspond to highly and least absorbing materials, respectively. The black spots in the X-ray microtomograph of the paint layer correspond to grains of the blue pigment, most probably natural ultramarine