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Category → non-invasive equipment

Finding The Culprit For Van Gogh’s Darkening Yellows

Van Gogh's Vase with Sunflowers is getting a pigment check-up this week. Credit: Wikimedia Commons.

The Sunflower still-life series is possibly Vincent van Gogh’s most famous work. Unfortunately the warm yellow hues that make the paintings memorable come from pigments that don’t have a long life-expectancy.

During the 19th century, chrome yellow pigments came in to fashion among painters and then quickly went out again, as artists realized that the vibrant yellow color was unstable and would lose its vibrancy when exposed to light.

For example, Claude Monet and Pierre-Auguste Renoir both steered clear of the chrome yellow pigments. But van Gogh threw caution to the wind and continued to use chrome yellow until his suicide in 1890—a tragic hint, perhaps, of his own instability and imminent breakdown.

This week, conservation scientists at the Van Gogh Museum in Amsterdam have been taking a closer look at chrome yellow pigments in Vase with Sunflower

, and a few other paintings, to learn more about the degradation problem.
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Stinky, Degrading Film And How To Stop It

Moldy Movies. Credit: Analytical Methods

Like humans, fungi have a taste for old movies. The problem is that they like to eat the film rather than watch it.

Adding insult to injury, fungi produce copious amounts of stinky odors from their consumption of classic flicks.

In fact, this fungi flatulence can cause headaches, nausea and irritated eyes in humans. (In particular, one airborne fungal molecule called 1-octen-3-ol.)

For this reason film archive staff fear any sort of mold on film reels: It means their precious collections are being destroyed by fungi.

Furthermore the fungal digestion produces smells that can make conservators sick.

That’s why the UK’s North West Film Archive approached researchers at Manchester Metropolitan University (MMU) to ask if there was any way to build a machine to detect the problematic odors.

Last week, MMU’s Craig Banks and his collaborator Gavin Bingley reported a handy new mold flatulence detection device.

With such a machine, conservators can test film reels donated from attics and basements. Sometimes these donations are so thick with dust it is hard to distinguish from mold—unless conservators take a sample and try growing it in a lab, Banks says. (Which then means the conservators may be exposed to the stinky molecules they’d much rather avoid.)

Another benefit of the device: If invasive fungi manage to sneak into storage areas, the detector can forewarn conservators about the moldy intruders before the growth gets out of hand—or is visible to the naked eye.

It’s worth pointing out that even if mold is kept at bay, old degrading film produces its own special brand of harmful flatulence. Continue reading →

Drilling Holes In To One Painting To Look For Another. Hmm…

Drilling into a Vasari painting to look for a da Vinci. Credit: National Geographic.

This blog devotes a lot of digital real-estate to cool experiments on art and artifacts that are non-invasive, or at least minimally so.

So I’ve got to admit that I was not particularly overwhelmed by the breathless reports last week in a myriad of media about a project to drill 14 holes into a Vasari painting in order to search for a possibly hidden da Vinci below.

The articles were subsequent to a press release by National Geographic on March 12, which was presumably trying to raise interest in a documentary about the project airing a few days later (March 18).

Yesterday the well-respected Art-Info published an interesting take-down of the drilling project, entitled “The Search for the Lost Da Vinci Fresco: Serious Science or Irresponsible Hype?”

The piece pointed to a protest-petition against the project signed by 530 members of the museum community, including high-profile curators at the Met and the Louvre.

According to the Art-Info article, none of these critical folks got face-time in the National Geographic Channel documentary. This is how the writer Kate Deimling put it:

“”Finding the Lost Da Vinci,” which aired on the National Geographic Channel on March 18, certainly looked like an infomercial for the project. The program’s narrator describes opposition to the drilling as a “media feeding frenzy” and an “attack from the press,” but none of the experts opposed to it is interviewed or even mentioned by name. Instead, scientists in lab coats decry the opposition to their work and are then seen boring holes into the painting while dramatic music plays.”

The Art-Info piece also voices criticism from the conservation science community, namely that the pigments detected by the drilling project might be from brick instead of paint.

Another criticism is that non-invasive analytical equipment (such as newer radar technologies) should be used instead of destructive drilling.

Bringing A Controversial Mural in LA Back To Life

By David Alfaro Siqueiros. From www.olvera-street.com

In 1932, David Alfaro Siqueiros got kicked out of Mexico for his political leanings so the artist spent six months in Los Angeles, California, where he produced a controversial mural called América Tropical.

Siqueiros may not be as well-known as his teacher and contemporary Diego Rivera, but these two, along with José Orozco, formed “Los Tres Grandes,” the big three Mexican muralists of the early 20th century.

During his stint in LA, Siqueiros was asked to paint a mural on a second story wall that overlooked Olvera Street, which was–and still is–a romanticized, somewhat kitschy Mexican market set up for tourists.

The idea was for Siqueiros to produce something that celebrated tropical America. The expectation was probably that it might be a romanticized vision of Mexico—just like the street below.

Instead Siqueiros, who was a die-hard Communist, produced a profoundly political piece of art: A crucified indigenous Mexican is at the forefront of the mural, with an American Eagle flying ominously above. A sharp shooter approaches from the right with his gun aimed at the Eagle.

To say the piece made a splash is a pretty major understatement. Continue reading →

Christians Artists Embellished Spain’s Muslim Paintings

The interior paintings of Granada's Madrasah Yusufiyya in Spain date from 1349. Credit: Carolina Cardell.

For nearly 800 years, the Islamic Moors occupied Spain, building extraordinary buildings that still draw hordes of tourists today. Case in point: the Alhambra.

Less well known is the Madrasah Yusufiyya of Granada, the only Islamic university from the Moorish era left standing in Spain. It was built in 1349 and operated for about 150 years, until the Christians conquered the region in the late 1400s.

The lovely Madrasah Yusufiyya was then used extensively by the Christians, most likely as administration buildings, says Carolina Cardell a conservation scientist at the University of Granada.

In fact the Christians liked the building so much, Cardell says, that in the last 500 years they have done a lot of touching up, repainting, restoring and embellishing of paintings covering the stucco and wooden interior walls of the Madrasah Yusufiyya.

Yet art historians haven’t really known the extent of these interventions. So over the past few years, while the Madrasah Yusufiyya has been under restoration, Cardell and her team of scientists took a closer look at the paintings with a suite of analytical technology. She’s just published a paper in Analytical Chemistry

about the interventions to the Madrasah Yusufiyya over the past 500 years. Continue reading →

Conserving Contemporary Art… And Your Favorite Mix-Tape

This light artwork involves a lot of electronic toy dogs suspended from plastic bags. This complex installation was made by Francisco Rocha.

I spent most of today learning about what museum scientists and conservators are doing to keep contemporary art in tip-top shape. (This whole week I’m at ICOM-CC, the huge art conservation science conference currently taking place in Lisbon.)

These folks who are developing life-extension treatments for some pretty quirky art and artifacts. I’m talking about gigantic chandeliers made from hundreds of illuminated plastic bags suspended from the ceiling, each bag containing a little electronic toy dog that barks and moves its legs. Gotta love it.

Or they’re working on sculptures made from random objects covered in aluminum paint that are now degrading beneath the metal veneer. Or Nazi typewriters found at bombed Gestapo headquarters. Continue reading →

Dating Silk With Some Fluffy (But Good) Science

Just a little fluff can reveal the age of silk artifacts, such as the age of this Egyptian textile from 900 A.D. Courtesy: The Textile Museum

Scientists at the Smithsonian have come up with a new way to figure out the age of ancient silk artifacts, such as flags, clothing and tapestries, using just a bit of fluff that’s fallen off the valuable textiles.

The only other scientific way to date silk is by carbon-14 dating, which requires about 100 times more sample than the new technique. (There’s another out-dated “stress-strain measurement” test, which as the name suggests, can put precious silk artifacts through some major mechanical procedures to do the dating. Sounds like just the perfect technique for getting on a textile curator’s black list.)

Anyway, the new technique monitors a component of silk called aspartic acid. Silk is essentially a bunch of intertwined proteins extruded from a silk worm, and aspartic acid is found within these proteins.

Aspartic acid can exist in two forms, the L- and D- forms, which have the same chemical formula but are mirror images of each other. When a silk worm extrudes the silk protein, the aspartic acid is only in the L-form, but over time it transforms into the D-form.
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Conservation Scientists Get Into The Vibe

Raman was used to identify the arsenic-based pigment on this Egyptian mask. Credit: Peter Vandenabeele

This week some 120 conservation researchers are facing the tragic hardship that comes from spending a week in Parma, Italy, where there is a conference called “Raman in art and archeology.”

This is not a conference about art made from tasty Japanese noodles. (That’s Ramen, silly!)

But if you caught the gratuitous pun in my headline, then you probably already know that Raman spectroscopy is an analytical technology that helps scientists study the vibrations and rotations that occur within molecules. Conservation scientists get giddy about Raman for a bunch or reasons, Peter Vandenabeele, an organizer of the conference, told me:

First: Raman is not picky about art. Which is to say that the technique can be used to study the chemical make-up of jewelry, oil paintings, Egyptian burial masks, glass, Mayan wall paintings… you get the picture.

Second: Portable Raman spectroscopy equipment is non-invasive, so it doesn’t hurt artwork. Scientists head to a museum, and shine low frequency laser light at a painting or sculpture which has mysterious molecular components that they want to know more about—such as a pigment that gives artwork brilliant color, or a pigment that is fading with time.
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The Peculiar Life Of The Dead Sea Scrolls

A Dead Sea Scroll containing Psalms text. Credit: Wikimedia Commons.

After spending more than two thousand years in peaceful hibernation, the Dead Sea Scrolls (DSS) have had a rough six decades. Discovered in several dry caves near the Dead Sea from 1947 through 1956, the texts experienced a series of travel and conservation adventures that border on mishandling, says Ira Rabin, a staff scientist at Germany’s Federal Institute for Materials Research and Testing (BAM).

Rabin has published several scientific papers on the Dead Sea Scrolls, which have historical and religious importance because they contain early versions of the Judeo-Christian Old Testament as well as other important Jewish writings. I recently met Rabin at a cafe in Berlin, where she described to me the potpourri of treatments that these texts—most of which are written on animal skin parchment–have received since their discovery.

The Dead Sea Scrolls have been covered in castor oil and glycerin as well as plastic consolidants (the latter of which is particularly unwise because no plastic stays in good shape for more than a few decades). Other treatments include Fuller’s Earth, a clay-like material, and being attached to glass plates using adhesive tape.
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Where Oh Where Were The Dead Sea Scrolls Written?

A Dead Sea Scroll text. Credit: Newscom.

In the late 1940s and early 50s, nearly 1000 manuscripts were found in caves along the banks of the Dead Sea at a site called Khirbet Qumran. The so-called Dead Sea Scroll texts, which include the oldest known versions of the Hebrew Bible as well as other important ancient writings, have long provided fodder for all sorts of academic research and debate.

One serious point of contention is whether the manuscripts were all written at Khirbet Qumran, or whether the caves were simply a library–a grotto-like repository.

Figuring out an answer to this question with science but without harming the precious documents is a tall order, but one that may be filled using a new technique developed by a team at the Technical University in Berlin, led by Ioanna Mantouvalou.

It turns out that the Dead Sea Scroll documents were penned on a real potpourri of materials, including copper, papyrus (a plant-based paper) and parchment (animal skin). Mantouvalou and her colleagues decided to focus on the provenance of the parchment-based writings because these form the majority of the Dead Sea Scroll collection.
Continue reading →