2 The widths of the planks that compose the upper support measure as follows, starting from
the left: 21, 46.5, 56, 49, and 13.5 cm.
3 The widths of the planks of the support’s lower section measure as follows, starting from the
left: 15, 38.5, 31, 40, 33, and 28.5 cm.
4 Of the several ways to guarantee that the heads or tips of nails do not contact the preparatory
layers, the most suitable method recreates a uniform support surface for the preparatory layers
by recessing the nail a few millimeters into the thickness of the support and then covering it
with a wooden plug. This method is most prevalent in the oldest works. In less careful prepa-
rations, pieces of cloth or parchment were applied with the aim of isolating the metal.
5 Amixture of paste, made with hide glue and sawdust, is frequently found in restorations of
painted wooden supports. This mixture shrinks in volume over time. The shrinkage produces
a tension in the area where paste was applied and in the surrounding areas, causing stress in
portions of the original wood that renders it weaker than before the application of the paste.
6 These crossbars were mounted in such a way that the attachment blocks also reinforced the
join between the upper and lower parts of the support.
7 In the adjustment of the frame junctures, the various pieces had been cut directly on the
painting, during which procedure the serrated blade scraped the painted surface.
8 The use of wedges for rejoining gaps and cracks in panels has already been treated by
Giovanni Secco Suardo in the first chapter of his manual Il restauratore dei dipinti (1866). This
system is still valid for the restoration operations described here. This method makes it pos-
sible to realign the disconnected edges and rejoin them perfectly through part or all of the
entire thickness, depending on the support condition, without tampering with the preparatory
and paint layers. With regard to destroying original material, it is important to limit such treat-
ment reasonably tothe areas ofexisting degr adation: the smaller the area of wood treated, the
greater the stability of the intervention. The wedge’s positioning, both with the grain and with
the annual rings, is important in obtaining the best stability between the panel and the added
inserts. The wedges must be placed radially with respect to the plane of the support.
9 The correction of the overall curvature was carried out after the V-shaped tracks were cut, so
as to prevent the back edges from pressing against each other during the correction and
thereby spreading apart the painted surface.
10 The mechanism consists of a brass shoe in the form of a closed U at right angles; it is 3 cm
long and 1 cm high and is held to the support with a screw. If the consistency of the wood is
poor, adouble-threaded brass bushing is used for attachment to the support; the external
threading anchors to the panel and the internal threading receives the screw that holds the
brass shoe to the support. This 1 cm diameter bushing is 1.5 cm high, according to the charac-
teristics of the support, and is screwed and glued to the planks with epoxy resin. Inside this
brass shoe glides a nylon slide with a screw at the center that is inserted into the thickness of
the framework; the hole has a cylindrical brass sleeve that receives a spiral spring inside it; the
upper end of the bolt is adjusted by a nut.
11 This type of intervention—even if it presents some difficulties with the possible removal of
the wax from the back of the panel—was considered useful given the precarious stability of the
painted surface.
12 The vacuum technique is very important for the consolidation of the preparation and paint
layers; its use requires a deep understanding of the application method, which is related to the
solidity of the support and to the particular characteristics of the paint.
13 The method used to carry out this measurement took advantage of a measuring device
sufficiently sensitive to plot the movement of the object in response to variations in RH. The
gauge is a suitable device for obtaining these measurements. Such an instrument—having a
centesimal scale and a useful field of 10 mm—was modified for use by the attachment to each
ofthe two ends (fixed and sliding) ofa perpendicular support ending with a 3.5 mm steel
sphere. On the back ofthe support, the reference couples were attached in a stable and easily
removable manner. These consisted of nuts with an internal hole ground to 3.5 mm, glued
with epoxy resin to three-prong thumbtacks that allowed the terminals of the sphere to be
housed stably.T R P P S: S C H 339