The Structural Conservation of Panel Paintings

characteristic isolation layer had fallen into disuse, as the construction

technique for the preparatory layers no longer required the presence of

the cloth as a buffer between the movement of the wood and the prepara-

tion.^1 The support is made of poplar—more precisely, white poplar

(Populus alba L.)—and is formed of two distinct sections: an addition was

made to the already existing support before the application of the paint

layers. Thus, the support consists of two sections united with a 13 cm

wide lap join. The connection is reinforced with glue, as well as with nails

that are driven in from both the front and back and bent under the prepa-

ration (Fig. 3). The upper section comprises five vertically oriented

planks.^2 The tree ring pattern is subradial, the quality is good, and the

presence of knots is rare. The lower section consists of six planks (also

oriented vertically)^3 of the same type of wood, with a medium tangential

cut. The planks of the entire panel, according to the customary technique

noted in the field of Italian panel paintings, are arranged with the internal

side facing the preparatory layer; they are butt-joined and glued together

with lime casein.

The variations in width of the planks in the two sections and the

method by which they are joined give the impression that the two sections

of the support may have been built at different times. It is certain that the

extension was made before the paint was applied, because the painting pre-

sents a single pictorial composition, as revealed by visual and IR readings

and chemical analysis of the pigments. Conversely, the preparation was

carried out at two different times. This last piece of information, as already

mentioned, is confirmed by radiographic studies that showed a greater

density of the lower part of the painting, caused by the greater thickness

of the gesso layer. Last, the ground and paint layers of the lower part are

in better condition than those of the upper part. This is also true for the

wooden support, whose condition can be attributed to the use of better-

quality wood, which was almost certainly obtained from a different tree

with denser fibers and greater resistance to attack by wood-boring insects.

A shaped frame (which is not the original) was placed along the perimeter

T R  P P S: S C H 319

Figure 3
Domenico Beccafumi, The Coronation of the
Virgin. Nail in the lap join ofthe painted
surface.