Photographic examination by infrared and X ray was carried out
toestimate the true condition of the remaining panel and paint (Fig. 8).
Infrared photography showed that there was extensive restoration down
the off-center vertical crack or join that runs vertically through the Virgin’s
face, as well as on some other, smaller areas of damage. The X ray showed
a very worm-eaten panel, in which most worm channels seemed to have
been filled with chalk, glue, and pigment. There were also several insets
ofa different wood in the complex vertical crack at the top and bottom
edges. The original panel had been planed down to a thickness of no
more than 2 mm. It was surrounded by thin oak strips, veneered onto
mahogany, and cradled with oak sliding bars and mahogany fixed battens.
The cradle had caused a slight concave warp on the length of the panel.
The painting’s poor condition had been exacerbated by these past
treatments, which were causing further cracking, blistering, and flaking.
The painting was also covered with a very discolored varnish. Restorations
covered original paint in some areas, and the surface was shown to be very
uneven under raking light. In order to improve these panel defects, extensive
panel treatment was proposed, involving the removal of all later additions.
After cleaning, the wooden inserts could clearly be seen from the
front (Fig. 9). Under raking light, it was also clear how badly the surface
had been affected, especially in the Virgin’s face. Before facing, a tracing
was made ofall the major cracks and problem areas for future reference,
as well as to relate the work to the back of the panel.S C P P N G, L 4111 0. Canv as ir oned onto th e ba ck of the
bal sa -w oo d bui ld up with wax resin- Sec ond la ye r of ba lsa wood
sa wn across the gra in
as the first la ye r
8. Se cond la yer of bal sa usu al ly
laid at rig ht angle s to th e first , sco red
on the undersi de as a ke y
5. Firs t la yer of balsa -woo d
pla nks la id with the
gra in runni ng in
sam e di rec tion
as the origi na l
pan el and
scor ed on
bot h si de s
as a key- First lay er of
bals a-w ood planks
sawn acro ss the gr ain
to half th eir de pt h at 2. 5cm
in te rv als after appl ica tion - Stabilt ex or polyest er ne t
im pr egnat ed wit h Beva 37 1 and ta ck
bonde d onto th e inte rl eaf (or panel) - Fin e open-we ave mu slin im pre gnat ed
wi th Beva 371 and tac k bond ed onto the pan el
Not e: On e or ot her in te rl ea f (o r both) can be us ed
7. Wax , dama r,
res in , an d wo od flour
pou re d ove r the first
laye r of balsa wo od- Wax , dam ar ,
resi n, and woo d flour
pou re d over the int erleaf
The bals a-w ood pl anks
ar e agita te d in to pos itio n
to disperse the air and
le ve l out the wa x mi xtu re- Orig ina l panel
Figure 7
Diagram of the new method of balsa-
woodbuildup.