Search

Information on the creation of a painting lies usually hidden under the surface. A painting's substructure may include the underdrawing, underpainting, modifications to the initial setup (or pentimenti), and sometimes even abandoned compositions. Traditionally, the study of these characteristics relies on penetrative, two-dimensional imaging techniques (infrared reflectography, x-ray radiography) complemented with selected paint crosssections. The limitations of this approach are twofold. First, it can be difficult to combine data from cross sections with two-dimensional images, because of poor redundancy of both methods. Second, cross sections involve destructive sampling of the paint layer. This paper introduces synchrotron radiation computed micro-laminography in the study of paintings. The technique allows for three-dimensional imaging of the paint stratigraphy in a nondestructive manner, enabling the imaging of paint layers, their interfaces, the ground, and carrier. The technique is demonstr...

X-ray radiography plays an important role in the study of artworks and archaeological artifacts. The internal structure of objects provides information on genesis, authenticity, painting technique, material condition and conservation history. Transmission radiography, however, does not provide information on the exact elemental composition of objects and heavy metal layers can shadow or obscure the ones including lighter elements. This paper presents the first application of synchrotron-based K-edge absorption imaging applied to paintings. Using highly monochromatic radiation, K-edge imaging is used to obtain elemental distribution images over large areas. Such elemental maps visualize the distribution of an individual pigment throughout the paint stratigraphy. This provides color information on hidden paint layers, which is of great relevance to art historians and painting conservators. The main advantage is the quick data acquisition time and the sensitivity to elements throughout the entire paint stratigraphy. The examination of a test painting is shown and further instrumental developments are discussed.

X-ray radiography is a common tool in the study of old master paintings. Transmission imaging can visualize hidden paint layers as well as the structure of the panel or canvas. In some medieval altarpieces, relics seem to have been imbedded in the wooden carrier of paintings. These are most probably thin organic fibrous materials such as paper or textile, which in traditional radiography are shadowed by the more absorbing surrounding material. This paper studies the application potential of synchrotron-based tomographic and laminographic imaging complemented with phase-contrast imaging for detection of such relics. The techniques are applied to a dummy painting. The results demonstrate that by using these imaging methods it is possible to three-dimensionally visualize hidden cavities in panels and detect thin fibrous low-Z materials sandwiched between a high-Z paint layer and a thick wooden panel.