T
wooden panels were a standard sur-
face for artistic painting. In such works of art, the rendering itself
typically receives intensive examination, whereas the panel sup-
porting the painting is sometimes evaluated simply as wood, with little
concern as to its species or characteristics. In modern conservation and
curatorial investigation, however, there is increasing appreciation for
the potential importance of identifying the wood of panels. Considering
the natural range of an identified species of wood may have important
implications as to the geographic origin ofa painting. It may become evi-
dent that individual artists or regions preferred certain woods or that some
woods were chosen over others because of properties such as dimensional
stability or ease of seasoning without defects. Finally, proper identification
ofwood is fundamental to conservation treatment when repair or replace-
ment is involved or when it is important to anticipate the properties or
behavior of a panel.
Simply stated, the process of wood identification usually involves
the visual recognition of anatomical features of the wood that singly or in
combination are known to be unique to a particular species or group of
species. Physical properties such as color, odor, specific gravity, relative
hardness, or reaction to chemical reagents may sometimes be helpful, but
the most important diagnostic features of the wood relate to its cellular
structure. Therefore, an understanding of the basics of wood anatomy is
fundamental to wood identification.
Visual features—that is, those apparent without magnification—
are the obvious starting point of the identification process and may pro-
vide at least an indication of the wood’s identity. In most cases, however,
portions of the wood must be examined under magnification. An initial
classification of an unknown wood is routinely made by observing features
evident with a hand lens on end-grain surfaces prepared with a razor blade
or sharp knife. Final determination, or verification of tentative visual or
hand-lens results, is best made on the basis ofminute detail observed in
razor-cut thin sections of wood tissue examined with a microscope.
For the more common woods, the necessary features for identifi-
cation are soon learned and memorized, and thorough examination of
macroscopic and microscopic detail gives an immediate identification.
Otherwise, the compiled characteristics can be compared directly with
samples of known wood, with photographs or descriptive reference
material, or with information in computer databases. Expertise in wood21R. Bruce Hoadley
Identification of Wood in Painting Panels