back of the support, and a central crossbar was installed. The framework,
made of chestnut, was anchored to the support with nine springs. The
springs were attached to the framework on one end and to the painting on
the other end with an equal number of small blocks (9 393 4 mm thick).
These blocks, made of the same type of wood as the support, were cre-
ated with a hole to house the end of the spring. They were attached in the
direction of the grain and glued in place. The blocks were placed inside
the framework, and a nearly 2 mm space perpendicular to the grain was
left to allow for possible expansion of the panel. Elastic control ofthe
warping is provided by the springs, primarily by those positioned in con-
formity with the central axis (Fig. 13). Thanks to its solid and stable
construction, the framework protects the edges and provides a secure sup-
port for the panel. This type of construction to control movement of the
support does not put any weight on the panel, as do traditional crossbars.
Instead, the panel is supported by anchor points distributed over the sur-
face. Because of the reduced size of the framework—corresponding to
the small size of the artwork—and the small blocks glued to the support,
which allow the springs to connect the framework to the panel, it is pos-
sible to reduce substantially the invasiveness of the intervention (Fig. 14).
In future conservation efforts, it may be possible to adjust the ten-
sion in the springs without tampering with the anchor points ofthe sup-
port. This use of springs to control deformation is best applied to supports
that consist ofa single board, as independent deformation of other boards
is not a factor. This structure can be closed on the back; the backboard cre-
ates a volume of air that functions as a buffer, slowing RH variations. The
wood used can be ofthe same type as the painting support. Such a device,
already described in the preceding intervention, slows climatic exchanges
between the back of the support and the environment. Because of the
small size ofthis painting, the back enclosure also provides increased sta-
bility to the support, augmenting the wood mass by filling up the frame-
work’s two cavities. To make this possible, the wood put inside the
framework must be oriented with the grain of the panel and placed so
thatit is completely independent of the panel. Naturally, the restoration
of the support also protects the back from wood-boring insects.328 Castelli
Figure 12
Temporary jig for adjusting the surface level.
Figure 13
Spring attaching the framework to the
support.