David Kirkpatrick

May 3, 2010

Recovering lost art through technology

Undoing 16th century vandalism in the name of religion.

The release:

Reveal-all-scanner for works of art

Research News May 2010

Painted-over murals were thought to be irretrievably lost because conventional methods are seldom suitable to rendering the hidden works visible without causing damage. Research scientists now aim to reveal the secrets of these paintings non-destructively using terahertz beams.

Link: download picture

Many church paintings are hidden from sight because they were painted over centuries ago. In the 16th century, for instance, Reformation iconoclasts sought to obscure the religious murals, while in later times the iconoclast images often were painted over once again. Several layers of paintings from various epochs can now be found superimposed on top of each other. If mechanical methods are used to uncover these pictures there is always a risk that the original work will be damaged. What’s more, the more recent layers and pictures on top of the original, which are also worthy of preservation, would be destroyed. Research scientists at the Fraunhofer Institute for Material and Beam Technology IWS in Dresden are now working on a non-destructive method for rendering these works visible, which involves the use of terahertz (THz) radiation. In the TERAART project funded by the German federal ministry of education and research (BMBF) they are cooperating with Dresden University of Technology, the FIDA Institute for Historic Preservation in Potsdam and the Dresden Academy of Fine Arts.

»We use THz radiation because it can penetrate the plaster and lime wash even if the layer is relatively thick. Unlike UV radiation for example, THz radiation does not damage the work of art. Infrared beams cannot be considered because they do not penetrate deep enough. Microwaves offer no alternative either, because they do not achieve the necessary width and depth resolution,« explains Dr. Michael Panzner, scientist at the IWS. A mobile system that can be used anywhere was developed to conduct the examinations. It consists of a scanner with two measuring heads which travels contactlessly over the wall. One measuring head transmits the radiation, the other picks up the reflected beams. The researchers were supported by the Fraunhofer Institute for Physical Measurement Techniques IPM, which built the adapted THz component.

»To produce the THz radiation we use a femtosecond laser incorporating the design principle of a fiber laser. The THz time domain spectroscopy technique applied by us utilizes the short electromagnetic pulses with a duration of just one to two picoseconds produced by the femtosecond laser. Each layer and each pigment reflects these pulses differently so that both a picture contrast as well as depth information can be obtained,« says Panzner. »The measured results provide information for example about the thickness of the layers, what pigments were used and how the colors are arranged. A specially developed software system puts the measured results together to form a picture displaying the structure of the concealed paintings.«

On a test wall, on which paintings in various types of paint were painted over with distemper, the scientists have already succeeded in revealing the structures of the concealed pictures. The next step will be to conduct a practical test in a church. The experts are also confident of being able to use THz radiation to detect the presence of carcinogenic biocides on and in works of art made of wood or textiles. »Preservationists will be very interested in our reveal-all-scanner for works of art, « affirms Panzner.

February 25, 2010

Art conservation and tattoo removal

As an occasional art conservator, I always find new developments in the field interesting. I don’t do painting restoration, but this technique sounds like it’s fairly unobtrusive and gets the job done. Plus lasers are always cool.

The release:

Laser surgery technique gets new life in art restoration

IMAGE: Art conservationists cleaned the two angels on the left with traditional restoration methods. They cleaned the one on the right using an advanced laser technique, which produced better results.

Click here for more information.

A laser technique best known for its use to remove unwanted tattoos from the skin is finding a second life in preserving great sculptures, paintings and other works of art, according to an article in ACS’ monthly journal,Accounts of Chemical Research. The technique, called laser ablation, involves removing material from a solid surface by vaporizing the material with a laser beam.

Salvatore Siano and Renzo Salimbeni point out that laser cleaning of artworks actually began about 10 years before the better known medical and industrial applications of the technique. Doctors, for example, use laser ablation in medicine to remove unwanted tattoos from the skin. In industry, the technique can remove paints, coatings and other material without damaging the underlying surface.

In the article, the scientists note that laser ablation has had an important impact in preserving the world’s cultural heritage of great works of art. They describe the latest advances in laser cleaning of stone and metal statues and wall paintings, including masterpieces like Lorenzo Ghiberti’s Porta del Paradiso and Donatello’s David. They also discuss encouraging results of laser cleaning underwater for materials that could deteriorate if exposed to air.

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ARTICLE FOR IMMEDIATE RELEASE “Advances in Laser Cleaning of Artwork and Objects of Historical Interest: The Optimized Pulse Duration Approach”

DOWNLOAD FULL TEXT ARTICLE http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/ar900190f

August 21, 2008

Possible light blogging coming up

Filed under: Arts, et.al., Media — Tags: , , , , — David Kirkpatrick @ 9:02 pm

Along with professional writing I occasionally work in the fine art conservation and preservation area. I blogged about one very cool project here.

Right now I’m getting into what looks like a major project that falls more under the historic preservation umbrella restoring some original iron work at Dallas’ Union Station. To the best of our knowledge this work is in the ballpark of 90-years-old.

Hopefully I’ll get the chance to get some images and do a post on this project, but in the meantime I might not blog as often as I do at times. I’m sure I’ll get a post, or a few, in each day.