The Structural Conservation of Panel Paintings

and dowel holes can easily be traced, revealing the differences in method

between one panel maker and another (Wadum 1987). In small panels

(48 3 63 cm) consisting of two planks, two dowels would normally be

placed in the join, whereas larger panels (75 3 110 cm) made ofthree

planks would have three dowels in each join. Smaller panels (50 3 60 cm)

made for portraits were sometimes composed of three planks—the middle

one wide and the two at the edges much narrower—so that there would

be no join down the middle of the panel that might run through the

subject’s face.

Lip joins and tongue-and-groove joins do occur in some instances;

the wedge-shaped joins are rarer (Fig. 7e–g). Additions on a panel made by

Michiel Vrient for Peter Paul Rubens show a refined Z-shaped chamfered

join (Figs. 7h, 9). This type of join was used to make a large overlap for

better adhesion when the grain of the added plank ran transversely in

H O  P-M T   N C 155

a bc

d ef

g h

Figure 7a–h
Different types ofjoinery ofplanks: (a) butt
join, (b) butt join with previous roughening of
the surface for better adhesion, (c) butt join
reinforced with butterflykeys on the front,
(d)butt join aligned with dowels, (e) lip join,
(f) tongue-and-groove join, (g) wedge-shaped
join, (h) Z-shaped chamfered join (mainly
used whereplankswith transverse grain are
assembled).

Figure 8
Maarten van Heemskerck, The Resurrection of
Christ,ca. 1550. Detail. Oil on panel, 172 3
131 cm. Department ofConservation, Statens
Museum for Kunst, Copenhagen. Original
butterflykeys on the front ofapanel (see
Fig.7c) show through the paint layer.