New Insights into the Cleaning of Paintings

198 • smithsonian contributions to museum conservation
FIGURE 1. Varnished painting surface is still visible through gel- saturated tissue.
• A very even level of varnish removal can be achieved that
conforms to the surface topography.
• The technique prevents solvent and dissolved varnish residues
traveling through cracks to the reverse of the painting,
a factor considered particularly advantageous in the cleaning
of both unlined and previously uncleaned paintings.
• Residues of varnish, old overpaints, and other non- original
material already present within the cracks in the paint layer
are dissolved and removed without being smeared and redeposited
across the painting surface (Figure 2).
• With the enclosed- pack system, the gelled tissues can be
prepared in advance under good extraction conditions in
multiple units. This ensures greater uniformity in gel distribution
between tissues and a reduction in both the conservator’s
exposure to solvent and the time required for the
tissue preparation.
Further advantages to be considered are the following:
• The gel- tissue technique prevents solvent movement (by capillary
action) through the painting structure, thus avoiding
the creation of new swelling fronts within the paint structure.
FIGURE 2. Simultaneous removal of varnish and old overpaints (including
nonoriginal material already present within the cracks in the
paint layer).