The restoration intervention that can address such conditions effectively
requires special solutions in methodology and technique.Diagnostic studies
Full-scale and detailed photographic documentation was carried out with
diffuse and raking light. Raking light photography revealed the type and
quantity of the lifting paint on the painted surface, as well as the support’s
deformation, especially in areas affected by cracks. Low-magnification
observation was all that was required to identify the wood species, as
the type of wood grain, the color, and the characteristic sheen of the
parenchymal rays left no doubt about its identification as oak. While
the RH was kept constant, relief drawings were made on graph paper to
determine whether the curvature varied after the cracks were rejoined.Construction technique
This small oil painting on panel consists of a single board of oak (Quercus
peduncolata or Q. sessiliflora). The board has a straight, horizontal grain,
with the tree rings positioned subradially. No knots or defects were noted
in the support. Cloth was not used for the preparatory layers. It was clear
that crossbars had never been used, both because of the painting’s small
size (26 3 37 cm and currently 3–4 mm thick) and because of the custom-
ary way supports were made in the LowCountries. In fact, for the great
majority of these panel paintings, deformation is controlled and the wood
fibers are supported horizontally and longitudinally simply by means of
the frame. The frame had a channel routed in its thickness that made it
possible to enclose the painting around the perimeter without restricting
eventual expansion and contraction. A few exceptions to this rule employ
reinforcement crossbars on the back.State of preservation
The painting presented diffuse lifting of paint along the grain of the wood,
as well as warping of the painted surface, which could be seen in three
pronounced curves. At the edges of these deformations were two cracks
that followed the grain, affecting the entire width. Although oak character-
istically has a mechanical strength, durability, and resistance to wood-
boring insects, the general conservation conditions were decidedly
precarious. The wood, especially along the borders, was eroded and fri-
able. The diffuse attack of wood-boring insects had produced many cavi-
ties, some of which had a diameter equal to half the thickness of the
support. The weakened mechanical resistance of the support fibers was
aggravated by a crossbar system that presented two drawbacks: it was
extremely rigid in comparison to the size of the painting, and it func-
tioned as a brace at a distance of only about 5 mm from the plane of the
support. The planing of the back of the support contributed to the deterio-
ration of the panel by causing the loss of the surface “skin” of the wood,
so that a more rapid exchange of moisture between the support and the
environment was encouraged.Previous restoration
The last restoration of this painting occurred in the early 1950s. At that
time, consolidation of the ground and paint layers, cleaning, filling of326 Castelli