Carbon 14 dating

Going back in time with a material

Carbon 14 is a radioactive isotope present in every living organism. When the organism dies, it decays at a known rate: measuring what remains makes it possible to estimate the age of the material, up to about 50,000 years.

Applied to a work, carbon 14 dating tells us the age of the support (wood, canvas, paper, parchment), of an element in ivory or bone, of a textile. It does not date the paint itself, except in rare cases of isolable organic binders.

It costs from €600 to €1,100 excl. VAT and takes three to five weeks, with a sample of a few milligrams.

AMS
Organic materials
Calibration
Limits

Dating in figures

€600 to €1,100indicative price excl. VAT

3 to 5weeks timeframe

50,000years of maximum range

a few mgof material taken

Datable materials

What can be dated
Material	Datable?	Remark
Wood (support, sculpture)	Yes	Date of felling of the tree, not of the sculpture
Linen or cotton canvas	Yes	Date of harvest of the fibre
Paper, parchment	Yes	Date of manufacture of the material
Ivory, bone, horn	Yes	Date of the animal's death
Metals, stone, ceramics	No	No organic carbon

Course of a dating

Choice of sample
Discreet area, minimal quantity, in the presence of the expert.
Pre-treatment
Removal of contaminations (glues, restorations).
Measurement
Accelerator mass spectrometry (AMS).
Calibration
Conversion of radiocarbon age into calendar age.
Interpretation
The expert compares the interval with the expected dating.

The Judgment of Midas, Nicolaes Clock (1589)

Date of the material, not of the work

The problem of calibration plateaus

The calibration curve has “plateaus”: between about 1650 and 1950, several calendar ages give the same radiocarbon age. Dating materials from this period is therefore not very discriminating.

On the other hand, for materials after 1955, the “nuclear bomb” left a signature in the atmosphere that carbon 14 detects precisely: a work supposedly earlier but whose support contains this signal is necessarily recent.

Useful or not very useful dating

Useful

Antiquity, Middle Ages, old tribal arts

Narrow interval possible
Strong exclusion value
Little calibration plateau

For works more than 400 years old.

Medal: In Commemoration of the Fiftieth Anniversary - The Warner and Swasey Company, Victor D. Brenner (1930)

Not very useful

1650 – 1950

Calibration plateaus
Interval too wide
Other methods preferable

To be avoided, unless a post-1955 signal.

Materials dated in 2024

Wood39%

Canvas and textile27%

Paper and parchment18%

Ivory and bone12%

Others4%

Source: partner laboratories (indicative).

Case study: a statue said to be ancient

A wood younger than expected

Situation

A wooden statue attributed to West Africa and dated to the 18th century is analysed.

Actions

A sample of three milligrams is taken under the base.
The dating gives an interval between 1955 and 1980.
The expert concludes it is a work of the second half of the 20th century.

Outcome

The certificate of authenticity of the stated period is refused.

From request to result

Week 0
Agreement
Analysis validated by the applicant.
Week 1
Sampling
In the presence of the expert.
Week 2
Laboratory
Pre-treatment and measurement.
Week 4
Result
Report and interpretation.

Flowers and Trees of the Four Seasons, Watanabe Shikō (early-mid 1700s)

Study for "Bathers at Asnières", Georges Seurat (c. 1883–84)

A methodological precaution

Leaf from a Psalter and Prayerbook: Ornamental Border with Carnations, a Thistle, and a Cook Ladling Soup (verso) (c. 1524) — **Dr. Amara N'Diaye**, chair of the certification committee

Vocabulary of dating

AMS: Accelerator mass spectrometry, precise measurement of carbon 14.
Calibration: Conversion of a radiocarbon age into a calendar age.
Plateau: Zone of the curve where several ages give the same result.
Bomb peak: Atmospheric signal after 1955.

Frequently asked questions

Does dating damage the work?

It requires a sample of a few milligrams, in a discreet and documented area.

Can the paint be dated?

Rarely: it is rather the support that is dated.

Is it mandatory?

No, it is proposed by the expert when it is useful.

Can dating prove authenticity?

No, it can only exclude it or make it plausible.

Useful documents

Contacts

Small Mosque in the Kaiserbagh, Felice A. Beato (1858)

Certification DepartmentParis — Headquarters+33 1 00 00 00 00certification@oimap.exampleMonday to Friday, 9 a.m. – 5 p.m.

See scientific imaging

A complementary non-invasive technique.

See imaging

Image credits (16)

Taj Mahal, Back View of the Rest-House, with Figure, Dr. John Murray (c. 1858–1862) — Cleveland Museum of Art, CC0 1.0
The Shepherd, Paulus Potter (1644) — Cleveland Museum of Art, CC0 1.0
The Judgment of Midas, Nicolaes Clock (1589) — Cleveland Museum of Art, CC0 1.0
Portrait Bust of a Man (27 BCE–14 CE) — Cleveland Museum of Art, CC0 1.0
Telescoping basket (1800's) — Cleveland Museum of Art, CC0 1.0
Carpenter's Plane (1400s) — Cleveland Museum of Art, CC0 1.0
Medal: In Commemoration of the Fiftieth Anniversary - The Warner and Swasey Company, Victor D. Brenner (1930) — Cleveland Museum of Art, CC0 1.0
Self-Portrait, John I Smart (1802) — 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
Study for "Bathers at Asnières", Georges Seurat (c. 1883–84) — Cleveland Museum of Art, CC0 1.0
Leaf from a Psalter and Prayerbook: Ornamental Border with Carnations, a Thistle, and a Cook Ladling Soup (verso) (c. 1524) — Cleveland Museum of Art, CC0 1.0
Small Mosque in the Kaiserbagh, Felice A. Beato (1858) — Cleveland Museum of Art, CC0 1.0
Jar with Stamped Decoration (1400s) — Cleveland Museum of Art, CC0 1.0
Fish or Seal Club (X’ús’) (late 1800s–early 1900s) — Cleveland Museum of Art, CC0 1.0
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
Portrait of a Man, Italian Painter — The Metropolitan Museum of Art, CC0 1.0