The Structural Conservation of Panel Paintings

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Table 1 Total (green to oven-dry) tangential and radial shrinkage percentages for selected woods

typically found in painting panels. For most woods, the values listed are estimates aver-

aged from various sources for the more common species of the genus. (For more exten-

sive listing of shrinkage values for individual species, consult the following references:

Chudnoff1984; Princes Risborough Laboratory 1972, 1977; U.S. Department of

Agriculture 1987.)

Shrinkage (%)

Common name Scientific name Tangential Radial

SOFTWOODS

Spruce Piceaspp. 7.4 3.6

Fir Abiesspp. 7.6 3.8

Pine, Scots Pinus sylvestris 7.7 4.0

Larch Larixspp. 7.8 3.3

HARDWOODS

Mahogany Swieteniaspp. 5.1 3.2

Walnut, European Juglans regia 6.4 4.3

Chestnut Castaneaspp. 6.8 4.0

Willow Salixspp. 7.2 4.2

Alder Alnusspp. 7.3 4.4

Cherry Prunusspp. 7.8 4.2

Ash Fraxinusspp. 8.3 5.2

Poplar Populusspp. 8.5 3.4

Maple Acerspp. 8.8 4.2

Elm Ulmusspp. 9.1 5.2

Lime Tiliaspp. 9.5 6.8

Oak, white Quercusspp. 10.2 5.2

Beech Fagus spp. 11.8 5.8

MC (%)

0 10 20 30

L

R

T

10

8

6

4

2

0

Sh

rin

ka

ge

(%

)

Figure 9
Relationship between MC and shrinkage in
the tangential (T), radial (R), and longitudinal
(L) directions. Plotted data represent a typical
wood such as poplar. Experimental results
ofcarefully dried wood are shown as solid
curves. As indicated by dashed lines, a linear
relationship is assumed for calculations of
approximate shrinkage behavior.