The Structural Conservation of Panel Paintings

It is important to keep in mind that a preliminary treatment of the paint

layer is necessary when repairs must be made to the support. This treat-

ment allows control of the cohesion and adhesion of the paint layer, as

well as facilitating effective elimination offillings and overpaintings.

Conservation or removal of reinforcements on the reverse

of the panel

The original reinforcing elements (Marette 1961), such as nailed cross-

pieces, are usually left in place; they are removed only if severe deteriora-

tion affects the front of the panel. Inlaid crosspieces that are blocked are

made mobile again or, if necessary, shaped according to the curvature of

the panel, as was done with an icon in the Louvre Museum (Fig. 1).

In cases of significant deterioration, original cross-grain elements

such as rabbet joints or decorative elements applied to the front are ren-

dered mobile and left attached to the support.

If reinforcing elements have been modified, or if some have been

added—as, for instance, a cradle—the conservators try to loosen the panel

to permit free movement again.

If the front of the panel shows significant deterioration, the ele-

ments applied to the reverse are removed, either completely or, if it is

sufficient for treatment, partially. Such was the case with a painting in

theMusée Condé in Chantilly, France, where only two vertical uprights

were removed and changed to allow the treatment of joints and fractures

(Fig. 2a, b).

Depending on the configuration of fractures or openings of joints that are

sometimes accompanied by distortions, interventions can be carried out by

means of simple gluings, which can sometimes be reinforced by V-shaped

grooves and wooden inlays. The conservators try to keep the angle of the

groove to a minimum, despite the results of the CTB study. This seems

more suitable to the actual cases we encounter, and it also results in the

least possible elimination of original wood. With the same concern for

the preservation of the support, the V-shaped grooves are made only at the

two extremities of the joint, as daily observation has shown that splits start

more often at the ends of a board—rarely at the center.

The tip of the incision is in the axis of the fracture, and it usually

reaches a depth of about two-thirds the thickness of the panel. The wood

used for the inlay is always one whose density is equal to or less than that

of the original material; it is sawn on the quarter and cut at regular inter-

vals to limit tensions.

When, because of significant wood shrinkage, the two edges of a

fracture are too far apart and can no longer be joined, a sliver of wood of

the same species is cut to size and inserted into the fracture. It is glued

along both sides to ensure renewed cohesion. When the joints cannot

be separated because of the complexity of their assembly, and the gap

between the two pieces is frontally visible and, therefore, aesthetically dis-

turbing, the sliver inserted is glued on one side only; this procedure allows

a reduction of the gap between the boards while preserving a clear reading

of the structure, and maintains the free play of the wood necessary to pre-

vent new fractures.

Treatment of Fractures

and Joints That Cannot

Be Separated

Repairs to Supports

254 Bret, Jaunard, and Mandron

Figure 1
School ofNovgorod, Crucifixion,sixteenth
century. Reverse. Tempera on panel, 71.2 3
57.3 cm. Louvre Museum, Paris. Detail of the
reverse of an icon, showing readjustment of
the inlaid crosspiece after shaping.