W
were traditionally made of
solid wood and consisted of either a single board or, for larger
panels, a series of boards edge-glued to form the required size.
Today a variety of wood-based panel materials are available as painting sup-
ports, including plywood, fiberboard, hardboard, and particleboard. Among
these types,plywood (in the sense ofwood with decorative face veneers)
has been known since ancient times, but machine-made commercial ply-
wood is of more recent origin. It appears to have found use as a support for
paintings in the latter halfofthe nineteenth century (Muller 1992). The
other wood-based materials are largely developments of the twentieth cen-
tury, with particleboard coming into general use only after World War II.
In the general sense, the term consolidationrefers to merging or
joining separate parts or to making something strong and stable or to
making it solid and compact. As used by conservators, the term refers to
remedial treatments of materials that have lost cohesion as a result of
deterioration, in order to stabilize an object and make it safe for its
intended use (Wermuth 1990). It is thereby understood that a material to
beconsolidated has some degree of porosity, so that another substance
can be introduced into the pore space to achieve a particular objective,
such as strengthening of deteriorated wood. Consolidation can therefore
be thought of as a kind of internal gluing. It is no accident that the theme
of the Tenth International Congress of the International Institute for
Conservation was “Adhesives and Consolidants,” as the difference between
the consolidation ofa porous material and the use ofadhesives to join
together something like the shards of a broken ceramic vessel is largely
one of scale (Brommelle et al. 1984).
The basic objective of consolidation is to assure the stability and
safety of an object. In addition, specific objectives will vary with the
intended use. The most demanding ofthese is when consolidation is
required to reestablish full functionality of an object. Usually this will be
the case when the object serves a significant structural function, as, for
instance, structural wood members in a building or the legs of a chair that
people will sit on. A less demanding level would be when stabilization is
required through all or most of the interior of an object. Finally, in some
cases, only a consolidation of surface layers may be required to prevent
damage by abrasion. Objects in museum collections would rarely require
reestablishment of full functionality but must be able to withstand some
handling and perhaps the rigors of shipping.87Consolidation of Wooden Panels
Arno P. Schniewind