The Structural Conservation of Panel Paintings

and exhibit sapwood on both sides (see Fig. 6). These characteristics were

found only in Rembrandt panels.

For Rubens and his workshop, it was proved that twelve boards

from different paintings were fabricated from the same tree (Fig. 11). Most

ofthe boards were used for the Medici cycle, which was ordered in 1621.

By comparing the earliest felling date, 1618, with the order date, it can be

surmised that the boards were seasoned only for a short time.

Beech wood

In central Europe, however, other woods—such as beech, lime, and

poplar—and conifers were also employed for art objects. With reference

to the experience gathered with oak, panels made of lime and beech wood

from early German painters were also studied; dendrochronological dating

was determined to be successful with the beech panels, while a chronol-

ogy for limewood could not be established.

In historical times, beech was rarely used in construction; thus it

has been impossible to establish a continuous chronology for dating beech

panels up to the present. Such dating has been achieved in approximation,

however, by comparative analysis based on oak chronologies. The positive

results permit the absolute dating of the mean chronological sequence

established from panels used by Lucas Cranach the Elder (1472–1553) and

his associates. From the analysis of Cranach’s signed and dated panels, it is

clear that only a few years had elapsed between the youngest annual ring

of each panel and its time signature. The determination of any given year,

however, is limited to the last growth ring available for measurement. As

has been discussed previously with regard to oak, it can be shown that

boards from the same tree were used for entire panels or as parts of

different panels (Figs. 12, 13). In comparison with oak panels, the number

ofboards extant from the same tree is extremely high for beech wood.

This finding can be explained by the fact that beech wood panels were

used only for a short time (1520–35) in the Cranach workshop and, fur-

thermore, that beech wood was used (with some exceptions) only in the

atelier of Cranach (Klein 1994c).

48 Klein

Rembra ndt

C.E.

16 23

Ba lt ic oak

135 0 1450 1550 16 50

Herman Doomer— NY 291001

Sel f-Port rait— THY 197 6.90

Alotta Adri aensz— ROT vdV 64

Chri st andAdulteress — LN 45

SaintJohn the Bapti st— B 828K

Sapwood

Figure 10
Dendrochronological analyses offive oak pan-
els ofRembrandt (all boards are from the
same tree). (B 5 Staatliche Museen zu Berlin,
Preussischer Kulturbesitz, Gemäldegalerie;
LN 5 National Gallery, London; NY 5
Metropolitan Museum of Art, New York;
ROT 5 Museum Boymans–Van Beuningen,
Rotterdam; THY 5 Coll. Thyssen, Madrid.)