The Structural Conservation of Panel Paintings

The Evazote/Plastazote is shaped to accommodate potential

panel warp. Only minimal rows of the foam blocks are used, to allow

flexing of the panel during environmental changes. This, of course, may

happen not only at the edges but anywhere across the width or length of

the panel, depending on its structure: restriction of movement is kept to a

minimum by this means.

The tray acts as a very substantial protection to a fragile panel,

both in its frame and during handling. If the environments are expected to

vary, slots can be cut in the tray backboard to allow greater freedom of air

movement and to reduce the possibility of concave warp from the front.

These slots should be covered with a porous material such as polyester

net. However, it is essential to have enough movement available for the

panel in the tray through use of blocks and edge slips that are sufficiently

flexible. These trays can usually be accommodated in the original frames

with a little adjustment, and the front edge of the tray can be toned or

gilded to form the inner rabbet of the frame.

Balsa-wood buildup

Balsa-wood buildup is often necessary when, following the removal of a

cradle or other veneered additions, a panel is too thin or weak for a tray.

The most commonly cradled panels are on poplar and are often thinned to

less than a third oftheir original thickness.

After a panel is released from a cradle and the cracks are consoli-

dated, it usually adopts a convex warp when seen from the front and may

also be too thin or too big to maintain a flat or near-flat conformation.

After moisture treatment where required, it may prove necessary to attach

408 Reeve

Poly eth ylene shapedto

edge andface of panel

toaccommodatemovement

andwarpin g

Cedarwoodinsert

toprovidefix ing

Oak tray frame

Fix in gscrews

Poly eth ylene

buttons

cutto support

th e panel

Panelpi cture fa ce

Venti latio n slotinbackboard

showin galu minumhoneycombcore

Slotiscoveredby a porous material

Hig her -density poly ethyle ne

at base of pi ct ure

Gaptoprevent

distortin gedge packing

when placin gbackboar d

Fib ergla ssandepoxyresi n

facin glayers to boar d

Figure 5
Construction elements ofa panel tray.