an intervening layer of balsa, shaped to follow the surface contours of the
painting, while the reverse was covered by a rigid sheet material (Bergeon
1985:104; Volle 1989:18). La Vier ge et les Saintsby Botticcini (Jacquemart
André), on which the double ground—thick chalk on the support and
thick gesso on the side of the paint layer—had split in two, was treated in
a similar manner. After several attempts to repair and preserve the sup-
port, it was changed to a metal honeycomb panel between two sheets of
fiberglass coated with epoxy resin; as in the previous example, it was fur-
nished with an interventing layer of balsa on the front and a sheet of oak
on the reverse (Volle 1989:19).
In the mid-1970s, after much experience with transferred paintings
being returned from exhibitions with signs of cleavage of the paint layer,
the Louvre decided that if the certificate of condition issued by the
restoration service mentioned “transfer,” a painting in such a weakened
state would not be allowed to travel.
The first backing the Huot studio did for the Louvre dates from1966.^65 The painting in question was thinned, placed on marine-grade ply-
276 Bergeon, Emile-Mâle, Huot, and Baÿ
Figure 8
Jacopo di Paolo, Le Couronnement de la Vierge.
Rev erse, detail. Musée du Petit-Palais (MI 428),
Avignon. Crossbar of two aluminum U-shaped
sections that slide on Teflon cylinders.
Figure 9
Jacopo di Paolo,Le Couronnement de la Vierge,
re verse. The half cleats that hold the sliding
crossbars are glued to the back of the panel;
they can be staggered on either side of the
crossbars.
Figure 7
Bartolo di Fredi, L’Adoration des bergers.
Reverse. Musée du Petit-Palais (C 71, inv.
20267), Avignon. This mobile support consists
of Carità sliding crossbars. The warp of the
boards was formerly straightened by incisions
made in the direction of the grain; the edges
were separated, and odd pieces of wood were
inserted in the technique known as
sverzatura.