sixteenth century (Fig. 1), or a large, complex altarpiece where the mold-
ing of the frame is securely attached, sized, and gessoed along with the
panel. An example is the San Pier Maggiore altarpiece by Jacopo di Cione,
most of which was removed from Florence and is now in the National
Gallery, London.^2 While there is evidence (such as the fixing of battens at
only one point on each vertical plank of the painting) that altarpieces were
constructed to allow small movements,^3 it seems likely that the relative sta-
bility of environmental conditions^4 within the church or chapel mitigated
the buildup of tension and stress, which could result in cracking and split-
ting. Elements of the San Pier Maggiore altarpiece, however, were proba-
bly glued, dowelled, and nailed together with battens—procedures that
produced a very rigid structure to counter the artwork’s size and weight.
In northern Europe, panel and frame construction tended to be
more sophisticated than in the south, and frames were routinely designed
to allow movement of the panel.^5 For example, the wings of the Oxburgh
Altarpiece, produced in an Antwerp workshop around 1530, have the pan-
els fitted, unglued, into grooves in the frame molding. Despite allowances
for movement, large altarpieces of this type are known to have suffered
from structural failure due to flaws in their original construction. For
example, it has been suggested that modifications had to be made to the
wings ofvan Eyck’s Ghent Altarpiece, as the wings proved to be too
heavy(Verougstraete-Marcq and Van Schoute 1989:78). In the case of the
Oxburgh Altarpiece, structural failure was a result of a restoration that
was based on a misunderstanding of the principles behind the original
construction. The free expansion and contraction of the panel in its frame
had produced a gap between the malrand(paint edge) and the frame edge.
This was filled and retouched—restorations that proceeded to restrict the
panel’s movement and cause splits in the panel and tenting and flaking in
the paint layer (McClure and Woudhuysen 1994:20–23). The rigidity of the434 McClure
Figure 1
Master of the Magdalen Legend (attrib.),
Emperor Charles V,early sixteenth century. Oil
on oak panel with integral frame, 34.3 3 23.8
cm. Fitzwilliam Museum, University of
Cambridge (2309).