For art's sake: Detect original and fake works

For art's sake: Detect original and fake works

By Renate Kant

SINGAPORE (JP): On Sunday, March 18, 2001, The Jakarta Post
ran an entire section of articles about art forgery with such
titles as Forged Art a Lucrative Business, Indonesia, the Land of
Fine Art Forgery and Forgery, Crime Plaguing Art World.

Excellent coverage on an important issue. In all articles,
however, an important component to this discussion was omitted, a
critical piece of the puzzle to help determine the authenticity
of a painting: a professionally trained painting conservator and
restorer has learned the skills to detect original and faked
works.

Art forgery is as old as the history of art itself. Already in
ancient Greece, there were excellent studios working with the
intention to pretend authenticity.

Most of these works of art--for example, on paper, metal work,
ceramic and paintings on panels as well as canvas--were created
to purposely manipulate the original artifact. It is well known
that in nearly all important museum collections, sometimes after
years, fake paintings are discovered which formerly represented
the icons of the exhibition rooms.

Their detection is not easy, as the aging of the materials
over a time span of centuries does not allow at once to
authenticate questionable works. Only laboratory research
together with stylistic comparisons in archives and collections
with undoubtable provenance could mostly help to verify
suspicious products.

Thomas Hoving, a former director of the Metropolitan Museum of
Art and an active fake buster, estimates that "a startling 40
percent of the art in the market are either
half-forgeries--genuinely old works that have to be doctored to
fit a more valuable style or artists--or are outright fakes.

Visual observation

Astri Wright, a Canadian-based art historian was quoted as
saying that the "experienced eye of someone trained in art
history can pick up these signs" of nuance of color, type of
paint and canvas used and other detail and features. I agree that
a trained eye can do this but in my 30+ years of experience
working with paintings of all media I have learned that art
historians as well as curators, art aficionados and artists
themselves are very often at a complete loss when manipulations
have done to a painting.

The eye of an art historian can be very useful, but regarding
the technological examination, I believe that she or he can be
easily misguided by aesthetic and theoretical reasons. However,
as the paintings we are facing in Southeast Asia are in general,
at the most 80 years old, it is easier to determine chronological
traces of the deterioration process by aging through a rough
comparison of the artist's work over several periods or through
research on paintings from the same timespan. By no means can a
work of Sudjojono or Hendra done in l960 be faked without
detection. Traces of this manipulation can always be
investigated.

Manipulation

What is meant by manipulation? Relining, for example, and
infusion of patinas (oil, glue) from the reverse side can cover
original traces. The use of tinted varnish may not allow
reflection of changes of composition in ultraviolet light. Parts
of overpainted damages and sections of thinned and overcleaned
areas may have disturbed the painted images.

Recycled canvasses and patches may have been used to stimulate
an aged torn canvas, or abrasion can be used to artificially
simulate the aging process. There are many other tricks of the
forger trade to apply touch-ups only in minor unimportant parts
of the composition to pretend that the main that the main work is
nearly oven-fresh.

These manipulated "damaged parts" can be covered with
nonreflecting tinted natural or synthetic coatings, a practice
often used in Europe, for example, when a historic painting of
the 17th or 18th century comes on the market. A professional
conservator immediately will examine changes of pigments,
diminished glazings, oxidated varnish layers, under the
overpainted coatings, etc.

I agree with Watie Moerani, head of the National Gallery
Jakarta, that "We feel like soldiers without weapons in fighting
art forgery" because there are few trained and experienced
conservators and restorers who can approach the doubtful pieces
with a solid practical analysis on the micro level. Visual
analysis of works together with laboratory research is most
effective.

Laboratory research

With the great advances made in the last decades in our
understanding of how chemical reaction takes place and how the
chemical systems can be identified, descriptions of deterioration
in terms of the process of activation and chemical changes that
occur has nowadays almost subconsciously entered into the polymer
chemist's day-to-day language.

The questions have to be clearly asked by the conservators and
I have experienced that well-trained chemists can demonstrate and
confirm beyond much doubts the mechanism of the chemical steps in
these challenging tasks.

The following research criteria must be considered to discover
more details that are hidden from the naked eye. There are the
new tools to detect fool-proofed faked works.

Conservators can more easily tell the authenticity and the
aging of materials went statistical laboratory test results can
be compared with similar findings from other works by the series
artists. Varnish and paint layers, for example, can be determined
in their aging (the oxidation of paint layers) by gas
chromatography. Cross sections of the painting will show
similarities with authentic works. Analysis of binding media and
the concept of composition or compositional changes can be shown
in infra red reflectography.

Even when historical materials are used (and which
"professional" forger will apply synthetic titanium white,
industrially produced since the beginning of this century, on a
still-life of the 18th century instead of a metallic lead white
well known to a darken as a photochemical result?) the chemical
changes that occur within a material are the criteria
conservators and laboratories have to determine.

But the critical physical changes as well, such as loss of
tensile strength, adhesive strength and folding endurance always
have to be related to the chemical tests. For example, there are
true indicators hat show whether change of chemical reactions
happen that allow judgment about the aging of material.

One particular test indicates the percentage of insoluble
matter in a coating and its ease of removal in solvent, the
ability to swell, insolubility, and the polarity of solvent
required to evaluate the onset of an unacceptable degree of
difficulty in removal of a picture varnish.

In another example, the measurement of yellowness in a film
may not closely relate to insolubility or brittleness. This
yellowness by photchemical and thermal aspects often shows the
authenticity of the age of a painting; however, the principle
chemical changes that occur within the material always have to be
tested in their reactions.

UV light tests can show traces of underpaint or changes of
composition. Natural science tests can be utilized such as
chemical binding media analysis, pigment analysis and material
endurance tests to prove the authentic stability of the media.

Underpainted areas on board can be detected by x-ray and
computer tomography.

Examples

For example, I started to take macrospecimens from the
painting I restored of the famous Indonesian painter Raden Saleh
and conducted tests in a German laboratory. The aim is to code
his specific choice of painting material in order to build up a
record of statistics. The specimens are cast in synthetic resin
and undergo microscopic research up to 140x enlargement with and
without UV light impact.

They provide proof for Raden Saleh's statement in one of his
letters that he used tinted varnishes as final coatings because
"they have to look like bacon or smoke."

For the 60 Hendras and 19 Le Mayeurs I have restored to date,
similar observations have been collected, but due to investment
reasons the specific analyses by natural science laboratories had
to be postponed.

When auction houses, public or private collectors ask for a
consultation, a conservator will give them a detailed report
about solvent tests, light reflection of coatings, aging of
materials and traces of possible manipulated changes. The
stylistic arguments are always important as a second approach. My
experience is that a well-respected auction house will pull the
painting back.

It is indeed a crime to forge a painting with the intent to
sell it off as an original. Art is an investment, and because
large sums can be spent on the work of artists considered already
to be of major value, it is more important than ever to have each
doubtful work examined and verified as to its authenticity. I
applaud all integrated efforts along these lines.

The writer is a museum-trained conservator and the director and
chief restorer of Singapore-based The Studio for Conservation and
Restoration--Renate Kant Pte Ltd. at
http//www.kantconservation.com.sg