faces of a panel. This system, called mobile backing, is also used for
extremely fragile supports.
Currently the Service de Restauration is making less use of the
châssis-cadre in favor of a specific r abbet arrangement for the frame. A
structure specifically adapted to the curvature ofthe panel, usually made
ofbalsa wood lined with Teflon and with flexib le attachments, allows
simple and effective maintenance of the perimeter (Fig. 7a–c).
Since few museums in France are climate controlled, and RH can
vary considerably throughout the year, treatment can be completed by the
use of a microclimate box that is secured to the back of the frame; the boxT C-R W P S 259Figure 5a, b
Cosmè Tura, Saint James the Great,fifteenth
century. Tempera on panel, 75.1 3 40.9 cm.
Musée des Beaux-Arts, Caen, France. The
reverse (a) shows the panel in a châssis-cadre
with a central support; the side view (b) of
the cornice shows that it is sawn at regular
intervals.
Figure 6a, b
Cosmè T ura, Saint James the Gr eat,re verse.
Two cleats that connect to the crosspiece are
shown (a); the detail (b) shows a cleat with its
double-spring support system.
abab