The Structural Conservation of Panel Paintings

of the timber, irregularities, or damage. No definitive rules can be fol-

lowed, but the amount ofmovement a panel is expected to make must be

considered. The depth of the frame or tray required will need to be con-

sidered if the curvature is expected to be great.

Grain orientation

Preferably, the grain of a painting panel should be vertical, because the

endgrain is less prone to accidental damage and compression and is best at

load bearing. When the grain is vertical, the flexible battens also function

more easily because the bottom edge is less likely to be trapped, as there is

no change in the angle of the bottom of the panel in relation to the tray’s

bottom rabbet. However, a panel with a horizontal grain direction can still

be accommodated by the tray and flexible support if attention is paid to

the weight ofthe panel and to its bottom bearing edge with regard to its

frictional resistance to movement.

Panel condition

In assessing the condition ofa painting panel, several points should be

considered, including worm damage; areas of sapwood; timber decay;

cracks; checks; repaired splits; original joins and rejoins; buttons,^5 insets,

“butterflies,”^6 and other kinds of repairs; and any other previous conserva-

tion work. All of these can affect the strength and modulus ofelasticity^7 of

the panel and must be considered in any assessment. No conclusive advice

can be given; however, the conservator must be confident that the panel is

strong enough to deflect the auxiliary support safely.

The flexible unattached auxiliary support, described herein as a

system for retaining and supporting vulnerable panels while allowing con-

ve x and concave movement, could also be considered as an alternative

(albeit a time consuming and complicated one) to conventional framing of

panels that do not require a support per se. In view of the number of pan-

els that are damaged by misconceived framing techniques, perhaps the

gr eater investment in time would be worthwhile.

A F U A S 375

a b c d e f

Figure 5a–f
When the cradle is removed from a cradled
panel (a), the panel (shown in five sections)
assumes typical curvature profiles (b–d) as it
moves toward an initial equilibrium (f ).