Cleveland Museum of Art · CC0 1.0Pages in this section
Spectroscopic analysesX-ray fluorescence, Raman and infrared: identify pigments, metals and binders to confirm or contradict the dating of a work.›
Carbon 14 datingDating the organic materials of a work — wood, canvas, paper, ivory, textile — by accelerator mass spectrometry.›
Scientific imagingInfrared reflectography, ultraviolet fluorescence, X-radiography, macrophotography and 3D survey: seeing below the surface without touching the work.›
When matter answers
An expert looks, compares, interprets. A laboratory measures. Scientific analyses confirm or contradict an impression: a pigment that did not exist at the stated date, a wood more recent than believed, an underdrawing that changes the attribution.
OIMAP relies on a network of 24 partner laboratories in 18 countries. They are chosen for the quality of their equipment, the rigour of their protocols and their independence from the market.
Three main families of analyses are offered: spectroscopy, carbon 14 dating and scientific imaging. Each has its own page; all are charged at the laboratory's actual cost.
The network in figures
Source: Certification Department, 2024.
Three pages to understand the analyses
How a laboratory is chosen
A laboratory is referenced after an audit covering its accreditation (ISO/IEC 17025 for testing laboratories), the qualification of its staff, the traceability of its samples, the validity of its methods and its conflict-of-interest policy.
It is audited every two years and takes part in interlaboratory comparisons to check that its results agree with those of its peers.
Referencing criteria
| Criterion | Requirement |
|---|---|
| Accreditation | ISO/IEC 17025 for the methods offered |
| Staff | Qualified scientists, trained in heritage |
| Samples | Documented chain of custody |
| Independence | No commercial link with the art market |
| Comparisons | Participation in interlaboratory tests |
The circuit of an analysis
- Decision
The expert proposes the useful analyses; the applicant gives their agreement.
- Sampling
If necessary, a minimal sample is taken on site, with photographs.
- Transport
Samples or the work travel under chain of custody.
- Analysis
The laboratory carries out the examination following a written protocol.
- Report
Results and limits are integrated into the expert's opinion.
As little invasive as possible
Non-invasive analysis or sampling
Non-invasive
Without touching the material- Portable X-ray fluorescence, imaging
- Carried out on site
- Surface information
First choice.
With sampling
Sample of a few fragments- Raman, FTIR, dating
- Carried out in the laboratory
- Precise information
If non-invasive results are not enough.
The milestones of the network
- First partnerships
Six laboratories in Europe.
- Common protocols
Standardised analysis sheet.
- Directive No. 2019-07
Analyses proportionate to the case.
- 24 laboratories
Presence in the five regions.
Case study: an anachronistic pigment
When matter contradicts history
A painting dated 1780 is submitted for analysis.
- X-ray fluorescence detects titanium in the white layer.
- Raman spectroscopy confirms titanium white.
- The expert concludes on an intervention after 1920.
The certificate is refused for the whole work; a modern retouching is documented.
A principle of humility
« A laboratory does not say whether a work is beautiful or even whether it is true: it says what it contains. »
Vocabulary of the laboratory
- Chain of custody
- Documented sequence of holders of a sample.
- Interlaboratory test
- Comparison of results between laboratories.
- Sampling
- Minimal sample of material.
- Anachronism
- Material that did not exist at the stated date.
Frequently asked questions
Do the analyses damage the work?
Non-invasive techniques alter nothing; a sample is microscopic and documented.
Who chooses the laboratory?
OIMAP, among the nearest referenced laboratories.
Can I have an analysis carried out elsewhere?
Yes, as information added to the file.
How much does an analysis cost?
From €250 to €1,100 excl. VAT depending on the technique, see the Prices page.
Useful documents
Contacts
Related pages
Certificates of authenticityThe OIMAP certificate of authenticity establishes, through independent expertise and scientific analysis, that the work is indeed the one claimed.›
ExaminationHow the condition of a work is observed, measured and recorded during a conservation examination.›
PricesIndicative scale of certification acts, laboratory analysis fees, reductions and payment terms.›
Choose an analysis
Image credits (22)
- Annunciation to the Shepherds: Leaf from a Book of Hours (1 of 6 Excised Leaves), Henri d'Orquevaulx (c. 1420–30) — Cleveland Museum of Art, CC0 1.0
- Jar with Stamped Decoration (1400s) — Cleveland Museum of Art, CC0 1.0
- Taj Mahal, Back View of the Rest-House, with Figure, Dr. John Murray (c. 1858–1862) — Cleveland Museum of Art, CC0 1.0
- Flowers and Trees of the Four Seasons, Watanabe Shikō (early-mid 1700s) — Cleveland Museum of Art, CC0 1.0
- Presentation Bowl (1900) — Cleveland Museum of Art, CC0 1.0
- Telescoping basket (1800's) — Cleveland Museum of Art, CC0 1.0
- Portrait of a Woman, Corneille de Lyon (c. 1540) — Cleveland Museum of Art, CC0 1.0
- Jar with Design in Underglaze Iron (1800s–1900s) — Cleveland Museum of Art, CC0 1.0
- Turtleback Reading Lamp, Tiffany Glass & Decorating Company (c. 1895–1902) — Cleveland Museum of Art, CC0 1.0
- Portrait of a Man, Louis Lafitte (1793) — The Metropolitan Museum of Art, CC0 1.0
- Leaf from a Psalter and Prayerbook: Calendar Page with Labors (recto) (c. 1524) — Cleveland Museum of Art, CC0 1.0
- Curtain (1600s–1700s) — Cleveland Museum of Art, CC0 1.0
- Fragment of a Border with Standing and Seated Birds Amidst Vegetation (1500s) — Cleveland Museum of Art, CC0 1.0
- Portrait of a Woman, Anna Claypoole Peale (1820) — Cleveland Museum of Art, CC0 1.0
- An Indigo Factory, Allahabad, Louis-Théophile Marie Rousselet (1865–68, published 1869–70) — Cleveland Museum of Art, CC0 1.0
- Salver, Carlo Bugatti (c. 1907) — Cleveland Museum of Art, CC0 1.0
- Peregrine Falcons (Duck Hawks), John James Audubon (c. 1827) — Cleveland Museum of Art, CC0 1.0
- Small Mosque in the Kaiserbagh, Felice A. Beato (1858) — Cleveland Museum of Art, CC0 1.0
- Fish or Seal Club (X’ús’) (late 1800s–early 1900s) — Cleveland Museum of Art, CC0 1.0
- Study of Hands (recto); Sketch of a Hand (verso), Pierre Lenfant (1700s) — Cleveland Museum of Art, CC0 1.0
- Coin of Demetrios, I (reverse) (200–190 BCE) — Cleveland Museum of Art, CC0 1.0
- Portrait of a Man, Possibly Sir Soulden Lawrence, John I Smart (1770) — Cleveland Museum of Art, CC0 1.0