Kolch quotes from a treatment proposal prepared by Richard
Buck in 1948 that clearly illustrates the thinking behind these treatments:Theweakness which contributed to the present disintegration lies in the
gesso which was added at the time the painting was transferred to its present
oak panel. This gesso is now chalky, and can be ruptured by minor tensions
or compressions which are transmitted to it by the wooden panel.... The
risk to the security of the painting can hardly be exaggerated. In order to get
atthis region of weakness, it will probably be necessary to remove the pres-
ent oak panel, replace the granular gesso support with a safer gesso layer and
rebuild a composite wood support which will relieve the dimensional com-
pressions now plaguing the paint. The composite panel I speak of is one that
was developed by George Stout and this laboratory, and has been used on a
number of paintings. Its particular merit is that it is almost completely unre-
sponsive to atmospheric variations. (Kolch 1977:41)Two of the last treatments carried out at the Fogg Museum
while Buck was there seem to lead directly to the balsa backings that
were characteristic of those done in the early 1950s at the Intermuseum
Conservation Association at Oberlin College, Oberlin, Ohio; this organiza-
tion is a cooperating group of museums that supported a conservation
center as a joint resource.
In 1950 a panel at the Fogg Museum that had been backed with
a secondary mahogany board was treated by removing the backing and
revealing the original panel. This panel was thinned, but no channels were
cut to reduce the warp, and, in fact, the warp was intentionally retained
when the back was reinforced with balsa boards (approximately 1.25 3
15 cm) that were adhered with a bulked wax-resin. These balsa boards
were oriented with the grain parallel to the original grain of the panel.
The last treatment Kolch describes from this period at the Fogg
Museum makes use of a grid of balsa blocks cut across the grain (Fig. 5).
This grid was applied to the back of a small circular painting with a his-
tory ofinsecurity; it had been treated with consolidants since 1939. Finally,
in 1951, the cradle was removed and the panel thinned to 2 mm. The treat-
ment record includes the following description by Buck:The insect tunneling was filled with a gesso-like mixture of polyvinyl acetate
and white inerts. Into this layer a piece of linen was pressed and allowed to
dry under moderate pressure. A new support was built by applying a wax
resin plastic filler, molten, to small rectangular crosscut blocks of balsa wood,R B: T D U B B P P 293Figure 5
Balsa-block backing, Fogg Museum
Laboratory, 1951.