Researching Analyzing Securing

Researching Analyzing Securing

RECENART® combines art historical research with state-of-the-art scientific techniques for authetication, dating and other forensic purposes.

RECENART®, the Eurpean art research centre in Finland, offers unique on-site, as well as portable, analytical services for the art world. Built on the infrastructure of the University of Jyväskylä, RECENART® has its foundation in the synergy of experienced art historians and innovative scientists. We provide concrete and unbiased research results about works of art and are devoloping a unique nano-tagging solution to secure your collection.

• Provenance research, authentication, attribution and dating

• Conservation

• Elemental & structural analysis and dating techniques: TES-PIXE, PIXE, XRF, SEM-EDS, raman, FTIR, XRD

• Optical analysis techniques: hyperspectral imaging, X-ray, photogrammetry, raking light, UV- and IR spectrographic analysis, stereomicroscopy

• Mobile laboratory: XRF, Hyperspectral imaging, Photogrammetry, USB-microscope, raman, Micro sampling equipment

Unique nanotechnology based tagging solutionRECENART®´s nanotechnology based tagging solution provides an invisible and a high level security mark for an art object. The tag consists of nanomaterial with a totally unique ‘fingerprint’. The tag is read and stored in our database. The tag guarantees the genuineness of the tagged art object and the works of art can be recognized as belonging to a certain art collection. The tag can be applied on any artwork without causing damage to it.

PhotogrammetryPhotogrammetry imaging provides a unique picture of a work of art. Multiple photos are taken from the object of art. Our program calculates the pixels in the object from every angle. The multiple images reveal the topography of the art object and therefore form a unique topography-based 3D picture of the item. The topography of the artwork cannot be forged. Photogrammetry can be combined with the nanotechnology -based tagging solution for security purposes.

• Style, Subject, Provenance, Technique and materials

One of the art historical research methods applied by RECENART® is attribution research. Attribution means the authorship of a work of art. To determine the attribution it is necessary to study the following points:

Together all these help us to contextualize the work of art.

Provenance means the chronology of the ownership, to include the custody or location of the art object from the time of its creation by the artist until the present day.

A documented provenance may strengthen the attribution to a specific artist and prove the authenticity of the work of art.

An accurate attribution and a complete provenance add value to the work of art.

Optical analysis techniques reveal what the eye cannot see from the art object. X-ray radiographic examination is very useful for detecting the changes in composition, in hidden artworks and over-painted areas. It also reveals damages and subsequent repairs carried out in the past. With the raking light examination the topography, painting techniques and any damages can be clearly seen.

Ultraviolet fluorescence and reflected ultraviolet examination uncovers any repairs or restorations, including retouching. Infrared examination enables the painting to be studied from underneath the visible surface, and it detects the underdrawings.

Stereomicroscopy is mainly used to examine the surface and paint layers. It facilitates sampling. With light microscopy it is possible to examine various samples and details, which are undetectable to the human eye. In RECENART we use mainly stereo and polarized light microscopy to look into the details of the art work. For microphotographs we use USB-microscopy.

Hyperspectral imaging

While traditional digital imaging takes three wide wavebands of digital light (red, green and blue), hyperspectral imaging captures  multiple narrow wavebands. RECENART® has hyperspectral imagers for visible  light and near infrared wavebands (VNIR, 450-850 nm) and for short wave infrared (SWIR, 1000 – 1700nm). Fine optical instruments combined with novel  computational  techniques make it possible to conduct colorimetric studies, determine the substances in the artwork, and reveal the underdrawings which may include erased text and hidden signatures.

CASE: RECENART®´s hyperspectral imaging team was asked to recover erased

text from a painting from the 20th Century.

“Herrn Hauptmann Swoboda

freundlich zugeeignet                                A. Puchka

 Juli 1925”

CASE: BlancheThe mobile laboratory can be moved to the artworks location. Here the hyperspectral imaging can reveal the sketching underneath the paint layers.

RECENART® is using several different state-of-the-art techniques to analyze the artworks at the elemental and the structural levels. Some of the techniques require a microscopic sample, but all of the techniques provide answers to the questions concerning what are the elements, the pigments, and other components of a specific art object. The elemental information is very useful in determining which pigments have been used and whether those pigments suit the specific era and the artist.

PIXE is the most sensitive non-destructive technique to study art objects. The University of Jyväskylä is using PIXE and TES-PIXE. TES-PIXE can be up to 10 times more sensitive than the regular PIXE due to its superior energy resolution. It can help detect elements in parts-per-million concentrations. This trace element information can be crucial in understanding where and how an object was created. The actual dating is often based on the impurities of the components.

Pigment analysis

It can be of great help in dating art objects. Pigments are inventions of time and place: certain pigments appeared on the market at different times and were also used only in specific places. By comparing the spectra of elements used in a certain art object with existing scientific data, researchers can acquire a solid empirical understanding of its physical nature. This provides art historians a deeper understanding of the history of the art object.

CASE: A portable XRF-spectrometer was used to carry out the pigment analysis of a late medieval wooden polychrome retable. The task was to determine a precise date for the object. The XRF-analysis indicated the presence of lead and tin in the yellow color areas. In the late medieval era there were two types (type I and II) of lead-tin yellows available for artists. Further analyses with SEM-EDS and polarized light microscopy proved the pigment as type I and this dates the retable to post 1450 AD.

Invasive testing is used when a microscopic sample is needed to gain more information from the artwork. The sample is taken under a microscope with the tip of an extremely thin needle. After sampling there are several different techniques to complete the research. The best analysis techniques are selected to obtain the required information from the samples. SEM-EDS is the most useful technique for examining the form and true size of single microscopic pigment grains and for analyzing their chemical composition. It is used for differentiating pigment look-alikes. For example, the same color can consist of different pigments and SEM/EDS can reveal their differences. Raman- as well as FTIR spectroscopy can provide the molecular and structural information of the pigment. X-ray diffraction analysis (XRD) is used to identify crystalline compounds, such as pigments and minerals. Carbon-14 dating can be used to determine the age of an object containing organic material. The technique can be used for both modern objects and objects that are thousands of years old.

A portable XRF-spectrometer is a piece of equipment for detecting  the key elements of inorganic pigments nondestructively.

Hanna Pirinen, Dr. Docent, Art HistoryTiina Koivulahti, Lic.Phil. Art History, Project Manager Seppo Hornytzkyj, Analyst in ChargeJanne Vilkuna, Professor, MuseologyIlari Maasilta, Professor, PhysicsTimo Sajavaara, Professor, PhysicsMikko Laitinen, Dr. PhysicsMikko Palosaari, Dr. PhysicsMika Pettersson, Professor, ChemistryJuhani Huuskonen, Dr. Docent, ChemistryMikko Väärämäki, MSc. ChemistryIlkka Pölönen, Dr. Computational data analysisLaura Aineslahti, M.Soc.Sc. Commercial Advisor

University of Jyväskylä, Art and Cultural Studies

Tiina Koivulahti, tiina.e.koivulahti@jyu.fi, +358 400 248 083Laura Aineslahti, laura.aineslahti@jyu.fi, +358 40 750 6415

www.jyu.fi/recenart