The Structural Conservation of Panel Paintings

ity, the large carved and gilded frame that held the panel not only served

an aesthetic purpose but had a structural function as well.

State of preservation

The painting had been immersed during the flood of 1966 in Florence.

During this time, the water, which was full of various materials, covered

four-fifths of the altarpiece for approximately eighteen hours. In the

Museum of Santa Croce, the panel was immediately protected with tissue

papers of various sizes that were made to adhere to the surface with

acrylic resin (Paraloid B72). Next the painting was moved to the limonaia

in the Boboli Gardens, where the humidity of the environment was pur-

posely kept at 90–95% to protect flooded artwork. The negative effects of

the immersion on the planks are well known; the initial reaction was an

expansion of the surface, after which the preparation and paint layer were

loosened by water. During the next phase, the various materials within the

painting dried at different rates, causing detachments and the overlapping

of the panel’s preparation and paint layers during shrinkage.

The initial papering done on site was repeated several times while

the painting was sheltered at the limonaia. The first intervention on the

wooden structure was the mechanical removal of the original crossbars.^16

Before this operation, the painting was laid flat and faceup on a wooden

structure that made it possible to work from below. Rectangular wooden

blocks applied to the back bridged the joins and attached to the planks by

two screws on both ends of the blocks. This served to reinforce the joins

in order to hold together the planks that made up the painting. When it

was brought to the laboratory at the Fortezza da Basso in June 1967, the

panel was already separated at the joins, with the exception of a small part

in the upper right of the last plank. The entire structure remained united

only bythe floating tenons that were left in the housings and held by the

dowels placed at the ends ofthe tenons. There were convex warps on the

painted surfaces of the planks, and two of the lower planks had become

concave and twisted in the longitudinal direction. The preparatory layers

were extremely deteriorated and unstable. The plugs placed to repair the

knots exhibited their own deformations: they had detached from their

housings and marked through onto the painted surface (Fig. 17). The par-

ticular characteristics of the deformations in this painting—related to the

T R  P P S: S C H 331

Figure 17
Fr ancesco Salviati, The Deposition from the
Cross. An original plug present in the painted
surface; it had come unglued during the
panel’s immersion in floodwaters during the
flood of 1966 in Florence.