In this series we're going to be taking an in-depth look at the entire conservation process
as it relates to one painting.
This untitled scene of Fifth Avenue in winter executed in oil on canvas by the American
impressionist painter Guy Wiggins arrived at the studio in need of desperate conservation.
The painting had an accumulation of surface grime and the old varnish had discolored,
the paint layer was heavily cracked and beginning to flake off in spots and the old conservation
work, completed sometime in the 1960's had begun to fail and was no longer serving any
beneficial purpose.
The clients had owned the piece for generations dating back to when Wiggins himself gave the
piece to a relative.
During that time the piece was generally well cared for though age and exposure to adverse
conditions had taken a toll on the work.
The clients were interested in conserving and restoring the piece and stabilizing it
for the enjoyment of future generations.
The first step in any conservation is the visual examination.
Looking at the painting to gather as much data as possible before touching it is essential
to understanding the piece as a whole.
In addition, looking at the old conservation to understand how and why it was done will
better enable its reversal and addressing of the underlying issues that prompted it.
While seemingly simple, the visual examination will allow me to get a better understanding
of the painting in its current state and afford me the time and headspace to consider the
materials and techniques that I may have to employ to achieve my client's desired result.
After the visible light examination we switch to ultraviolet or blacklight, which allows
the conservator to observe the fluorescence of the materials and gather more information
that may not be clear to the naked eye.
This examination can reveal old retouching, new materials, help differentiate between
mediums, pigments and varnishes.
Learning how to read the fluorescence takes years of practice and can be more of an art
than science.
Deep purples can often be read as old retouching or recently added pigment; bright greens can
be seen as discolored layers of varnish.
Then again, some pigments such as zinc and titanium white naturally fluoresce even if
they're original and masking agents such as shellac and polyurethane are employed to conceal
the newer work and all but prevent the UV light wavelength for being an effective tool.
In addition to all of the time spent looking at the artwork it's helpful to spend some
time on the artist.
By researching the painting and the artist we can learn about their working process,
the materials they may have used and if there are any potential issues that lie in wait.
Further, if we can learn more about the artists' body of work and vision we can better execute
the conservation with that in mind.
In addition, as this work was previously conserved we can investigate the materials and techniques
that were common during the 1960's in an effort to avoid costly scientific testing and better
prepare for the work ahead.
After all of the visual examination and research is concluded we can move to the physical testing
of the materials.
Detailed notes are essential and will be referenced multiple times as the conservation proceeds.
A small sample of the lining adhesive is taken from the tacking edge and stored for testing.
As the lining will be removed it may be necessary to send this sample to a lab if it's composition
cannot be determined locally.
The first step in cleaning a painting is removing the grime that can consist of dust, dirt,
cooking oils, cigarette smoke, chimney and furnace soot and other particulate matter.
The chemicals used to remove the varnish often have difficulty penetrating through the grime
layer which can lead to the use of increasingly stronger and more aggressive solvents which
is not only unnecessary but can expose the paint layer to the possibility of damage.
Starting with distilled water we will work our way through various detergents, enzyme
solutions, soaps and other agents until we find one that is effective.
These small tests are conducted in inconspicuous areas usually at the edges of the painting
that is covered by the frame rabbet.
Once an adequate cleaner has been identified for the grime the testing of the varnish can
begin.
Natural resin varnishes can yellow over time with exposure to ambient UVA and UVB light
or become cloudy and brittle.
Starting with the mildest of solvents and varying in composition and increasing in strength
the areas where the grime was removed are tested until the varnish is adequately and
safely removed.
It is often necessary to test different areas of the painting as different paint colors
or brands can have different reactions to the same solvent.
That is, while the white may be stable, the blue may be fugitive and the cleaning approach
must vary to reflect this.
Relying on years of experience and research we can narrow the possible lining adhesives
before we make any tests.
By observing the sample's reaction as well as using the sense of smell the identification
of the adhesive as rabbit skin glue allows the removal approach to be determined.