B

  with balsa-wood blocks glued with wax-

resin is an uncommon technique rarely used by the Institut Royal

du Patrimoine Artistique, Brussels (IRPA). In ten years, it has been

applied to only about ten paintings. These were oil paintings on oak panels

from the sixteenth or seventeenth century that needed to be reinforced,

maintained, or constrained for stability or display. At IRPA, reflections

re garding this type of treatment have been based on the published descrip-

tions of several authors (Buck 1970; Spurlock 1978; Beardsley 1978; vom

Imhoff1978).

Since at IRPA reversibility is considered to be an absolute require-

ment for an adhesive, we opted for damar wax-resin rather than a tridi-

mensional resin. Subsequently, collaborative work with our French

colleagues^1 as well as comparative studies made by students (Habaru

1990–91; Mori 1992–93) have enabled us to refine this technique. Each

intervention has led to discussion and research aimed at improving the

technique and adapting it to the specific problem of each panel.

First, the two types of deterioration of painted panels that we

believe justify a balsa backing will be described. The choice of materials

and work method will then be explained.

Fr equently, panels are found whose original construction has been altered

by earlier, well-intentioned restorers. The history of treatments for paint-

ing supports has seen many changes in fashion. Some problematic panels

underwent the addition of crosspieces, cradling, or even transfer. To

perform these so-called restorations, the supports were thinned down

or eliminated.

Today these restorations are faulted, first, for radically transforming

the structure of the work and, second, for proving ineffective. Moreover,

the irremediable loss of technological and historical evidence is very unfor-

tunate. These restorations must now often be reversed to save the lifted and

distorted paint layer. Once the additions have been eliminated, we are left

with a work whose support is so thinned down that it is no longer able to

stand by itself.

The backing of these thinned-down panels with balsa-wood

blocks adhered with wax-resin presents a significant advantage—namely,

the method is easily thermoreversible. Because it is made up of a multi-

tude of waterproof cells whose pure cellulose walls are difficult to perme-

Reinforcement of

Thinned Panels

364

Jean-Albert Glatigny

Backings of Painted Panels

Reinforcement and Constraint