Today, carbon-14 dating is much more than just a method used by archaeologists. Thanks to advances in analytical techniques, it is used in many fields, including the study of archaeological remains, the authentication of works of art, the testing of bio-based materials, the protection of biodiversity, and scientific research.

The basic principle remains the same: measuring the amount of carbon-14 present in an organic material. However, its applications vary depending on the objectives and the materials being analyzed.

In this article, learn about the main areas of application for carbon-14 that the CIRAM laboratory is working on, as well as the specific challenges associated with each one.

The Main Applications of Carbon-14

In archaeology: establishing the chronology of the remains

Carbon-14 dating is one of the primary dating methods used in archaeology. It allows researchers to date a wide range of organic materials—such as charcoal, bones, teeth, seeds, textiles, and peat—in order to place archaeological finds in their chronological context.

When combined with other methods such as thermoluminescence (TL), OSL, or isotopic analysis, this method helps reconstruct the history of archaeological sites and ancient populations.

Check out:

• How does carbon-14 dating work?
• Carbon-14 dating for preventive archaeology
• How is carbon-14 dating used to date bones?
• Carbon-14 Dating of Peat
• Reservoir Effect: Dating Marine Organisms
• Comparison of Carbon-14, TL, and OSL

To authenticate works of art

In the field of cultural heritage, carbon-14 dating is used to determine the age of a work’s organic materials: wood, canvas, paper, ivory, or textiles. The results help verify whether the material is consistent with the stated period of creation.

For materials produced after the 1950s, the post-bomb effect even provides a particularly high degree of accuracy and makes it easier to detect recent forgeries.

To learn more about this topic:

• Carbon-14 dating of paintings
• Carbon-14 dating of ivory
• Carbon-14 Dating of Wooden Sculptures
• Enhanced carbon-14 dating dedicated to Tribal Art
• Carbon-14: what is the post-bomb effect?

To analyze bio-based materials

Carbon-14 is not used solely for dating. In industry, it is also used to measure the proportion of carbon of biological origin and to distinguish bio-based materials from fossil-based materials. This analysis meets the requirements of numerous standards and certifications applicable to plastics, paints, cosmetics, and fuels.

Here are a few examples:

• What is a biobased product?
• ASTM D6866 and radiocarbon analysis
• Carbon-14 dedicated to biopolymer analysis
• Analysis of recovered fuels: why use carbon-14?

Olivier Bobin

Olivier holds a master’s degree in chemistry (1996) and a Ph.D. in Archaeomaterials Physics (2001) from the University of Bordeaux. In 2005, he co-founded the CIRAM laboratory with Richard Chéret, and today serves as its co-director and scientific director.

Accurately dating an object or a work of art involves much more than a simple chronological measurement: it enriches knowledge, confirms authenticity and enhances the value of the work. Carbon-14 dating, a technique that has been in use for over 70 years, remains the benchmark method for analyzing organic materials, from archaeological remains to ancient works of art.

But how does this method actually work? Which objects can really be dated? And above all, what guarantees does carbon-14 dating offer in terms of scientific reliability?

Dans cet article, nous vous proposons d’explorer les fondements de la datation au carbone 14, ses domaines d’application, son déroulement, ses limites et les éléments qui conditionnent la fiabilité des résultats.

Understanding carbon-14 dating: principles and operation

Often used as a tool for authentication or absolute dating, carbon-14 dating is an analytical technique based on a physical principle that is as robust as it is precise. It offers professionals an essential scientific method for reliably and documentably dating organic materials.

The basic principle of carbon-14 dating

Carbon-14 dating was developed in the 1940s by American chemist Willard F. Libby, and rapidly revolutionized the human sciences. Libby achieved the first radiocarbon dating in 1949, a breakthrough that earned him the Nobel Prize in Chemistry a year later. 

The principle of carbon-14 dating is based on the natural decay of a radioactive carbon isotope: carbon-14 (14C). This radioactive carbon isotope is present in minute quantities in the upper atmosphere. It is formed by the interaction of cosmic rays with nitrogen 14, causing a transformation into carbon 14. It is then absorbed by the biosphere (plants, animals, humans).

A la mort d’un organisme, celui-ci cesse d’échanger du carbone avec l’environnement, et la décroissance radioactive du 14C peut débuter. Ce phénomène permet de dater la mort de l’organisme avec précision. On appelle “demi-vie du carbone 14” le temps nécessaire pour que la moitié du 14C se désintègre, celle-ci est estimée à 5 730 ± 40 ans. Il est important de noter que les premières datations utilisaient une valeur conventionnelle de 5 568 ans, ce qui explique certaines différences d’interprétation dans la littérature ancienne.

De la mesure du carbone 14 à la datation

This enables scientists to measure the ratio between residual 14C and 12C in a sample (wood, bone, textile, ivory...). They also apply isotopic fractionation corrections (natural variations in the 12C/13C ratio) to standardize results.

Unlike relative dating techniques, which establish chronological relationships between objects, radiocarbon dating provides absolute dating, with an accuracy of just a few decades.

La méthode s’est largement perfectionnée depuis sa formulation par Libby, notamment avec l’apparition de la spectrométrie de masse par accélérateur (AMS). Les résultats s’expriment alors en années « Before Present (BP) », le « présent » étant fixé conventionnellement à 1950, date de référence scientifique.

From laboratory to analysis: how does carbon-14 dating work?

L’analyse carbone 14 suit un protocole rigoureux et codifié. Dans un premier temps, le laboratoire procède ainsi dans un premier temps à un prélèvement contrôlé. L’échantillon est ensuite purifié afin d’éliminer toute contamination (colles, vernis, conservateurs…).

The most widely used technique today is gas pedal mass spectrometry (AMS). It enables carbon-14 atoms to be counted directly, even on minute samples of the order of a few milligrams. Before this step can be carried out, the material must be converted to pure graphite, then ionized and accelerated for extremely sensitive analysis. This technical step requires precise know-how and highly specialized equipment, which only laboratories specializing in carbon-14 dating possess (with a few exceptions).

Après la mesure, les résultats bruts sont ajustés grâce à des courbes d’étalonnage internationales (comme IntCal20) pour compenser les variations du taux de radiocarbone dans l’atmosphère à travers le temps. En effet, des phénomènes naturels comme l’activité solaire, les champs magnétiques ou les émissions anthropiques peuvent influencer cette calibration.

Please note that certain contexts require special precautions, such as the effects of marine or river reservoirs (concentration of old carbon in water), or the phenomenon of old wood, when the material used in a work is older than its creation. These specificities are taken into account by the analysis laboratory to enable precise dating of the sample analyzed.

Applications and limitations of carbon-14 dating

La datation carbone 14 n’est pas applicable à tous les objets. En effet, avant d’initier un processus de datation, le requérant doit savoir quels sont les matériaux compatibles, sur quelles périodes cette méthode est-elle fiable, et comment interpréter ses résultats dans le cadre d’une expertise professionnelle.

What objects and materials can be carbon-14 dated?

The carbon-14 dating method can only be applied to organic materials: wood, bone, ivory, teeth, plant textiles (linen, cotton), leather, charcoal, plant fibers, pigments containing organic binders, and so on.

Cette analyse est incontournable en archéologie, sur plusieurs applicatifs comme : dater des habitats, sépultures, structures anciennes ou des objets du quotidien. Dans le domaine de l’art, elle permet de vérifier l’authenticité d’œuvres de la datation de sculptures en bois aux objets ethnographiques, d’icônes, d’instruments de musique ou encore de toiles.

It is also invaluable for identifying counterfeits, since it can detect modern copies or undocumented restorations.

Reliability, precision and limitations of the method

The reliability of carbon-14 dating results depends on several criteria:

• État de conservation de l’échantillon
  Qualité du prélèvement (représentativité, absence de contaminant)
  Méthode utilisée
• Rigorous chronological calibration

La précision de la datation peut atteindre quelques dizaines d’années pour les deux derniers millénaires. Mais elle peut s’étendre sur plusieurs centaines d’années pour des objets très anciens. La méthode atteint une limite théorique d’environ 60 000 ans. Dans la pratique, les scientifiques interprètent toutefois avec prudence les résultats obtenus au-delà de 45 000 ans, car le signal résiduel devient extrêmement faible.

Enfin, il est important de garder à l’esprit que la méthode date la mort de l’organisme (abattage de l’arbre, récolte du lin, mort de l’animal) et non celle de la fabrication de l’objet. Une lecture croisée avec les données stylistiques, historiques et technologiques est donc indispensable. Le laboratoire peut également associer la datation radiocarbone à d’autres méthodes d’analyse pour compléter les résultats. 

Pourquoi faire appel à un laboratoire spécialisé ?

Obtenir une datation carbone 14 ne consiste pas uniquement à mesurer l’âge d’un échantillon. Le laboratoire interprète les résultats à partir de plusieurs éléments : le matériau analysé, son état de conservation, les contaminations possibles, le contexte d’étude et la calibration des données.

C’est pourquoi le choix d’un laboratoire spécialisé est essentiel. Son rôle va au-delà de la simple mesure : le laboratoire vérifie l’adéquation du prélèvement, applique les protocoles analytiques appropriés et accompagne l’interprétation des résultats pour garantir une datation fiable et exploitable.

La datation au carbone 14 demeure aujourd’hui une méthode de référence pour dater les matériaux organiques utilisés en archéologie et sur le marché de l’art. Bien connaître son fonctionnement, ses domaines d’application et ses limites permet de choisir la stratégie d’analyse la plus pertinente pour chaque objet.

Pour aller plus loin, un laboratoire spécialisé comme CIRAM peut vous accompagner dans le choix de la méthode, le prélèvement des échantillons et l’interprétation des résultats afin d’adapter l’analyse à votre problématique.

Olivier Bobin

Olivier holds a master’s degree in chemistry (1996) and a Ph.D. in Archaeomaterials Physics (2001) from the University of Bordeaux. In 2005, he co-founded the CIRAM laboratory with Richard Chéret, and today serves as its co-director and scientific director.

Scientific dating plays a vital role in the fields of art and archaeology, whether for the preservation of cultural heritage or in relation to financial considerations (sales, insurance). It makes it possible to verify the age of an object, clarify its provenance, or authenticate a work of art.

One of the most widely used techniques is radiocarbon dating, commonly known as carbon-14 dating, which remains an essential benchmark. This technique is very useful for dating organic materials such as wood, bones, and textiles. However, as effective as this method may be, it is not suitable for all types of materials or all historical periods.

In this article, we explore the limitations of carbon-14 dating and the complementary methods used depending on the materials and contexts under study.

What carbon-14 dating can and cannot do

Although radiocarbon dating remains an essential reference in the study of ancient organic materials, it doesn't meet all requirements, especially as objects become more complex. It is therefore crucial to understand the context in which it is applied, in order to choose the most appropriate method for each case.

The principles and benefits of carbon-14 dating

Carbon-14 dating is based on a well-established principle: measure the amount of the radioactiveisotope ¹⁴C still present in an organic sample, then deduce its age. This method is effective for dating formerly living materials: wood, bone, shells, textiles, leather, paper or even charcoal that can be found in the analyzed object.

In most contexts, its reliability is beyond question. The method can generally provide a coherent chronological range, extending to around 60,000 years, with relatively controlled margins of error. This is particularly the case when conservation conditions are good and sampling is carried out using optimized protocols.

This dating method is particularly prized for validating a period hypothesis, building a conservation strategy, or simply consolidating the historical traceability of an object. When appraising a work of art, such as a medieval parchment or a fragment of funerary cloth, ¹⁴C dating offers a legible, documented scientific argument.

The technical, material and temporal limits of carbon 14

Despite its many advantages, radiocarbon dating has significant limitations in terms of its applicability. First of all, it is limited exclusively to organic materials. Metals, ceramics, mineral pigments, glass, and stone cannot be dated directly using this method.

Secondly, its accuracy diminishes the further you move away from its optimal study window. After 60,000 years, there are not enough ¹⁴C left to obtain a usable date. Conversely, objects that are too recent can pose problems, not least because of the effects induced by human activity (e.g. nuclear testing due to the post-bomb effect) on atmospheric radiocarbon content.

Other factors can distort results, such as poorly documented restoration, contaminated sampling or aggressive chemical cleaning. Finally, a crucial point must be stressed: carbon-14 dates the raw material, not necessarily the use or manufacture of the object. A piece of furniture made from old wood, or a painting done on a reused support, can thus induce a biased reading if the analysis is poorly contextualized.

In such cases, it is essential to call on the expertise of a specialized laboratory, which can use other analytical tools to cross-reference data and guarantee reliable dating.

When should other dating or analysis techniques be preferred to carbon-14 dating?

In certain situations, the limitations of carbon-14 dating mean that other approaches are required to obtain a reliable reading of the object studied. This is particularly the case when the materials are not organic, or when a more complete analysis of the context is required.

Alternatives for inorganic and complex materials

When the objects under study are made of ceramic, glass, stone, metal, or inorganic pigments, carbon-14 dating cannot be used to date them because there is no organic material to analyze. In such cases, other dating techniques are used, selected based on the specific characteristics of each material:

Other approaches, such as uranium-thorium analysis, can be considered depending on the specific characteristics of the materials and the context in which they are used. At the same time, more detailed physico-chemical investigations can be carried out to study patina layers, corrosion or material composition, in order to guide indirect dating.

Crossing methods: the key to reliable, interpretable dating

Lorsque le carbone 14 ne peut pas être appliqué ou lorsque son interprétation reste insuffisante, un laboratoire spécialisé peut recommander une méthode complémentaire adaptée au matériau étudié, comme la thermoluminescence, l’OSL ou l’ESR.

The combination of several dating methods, coupled with an interdisciplinary approach (materials science, art history, archaeology) is often essential in complex cases, such as those involving composite objects, restorations or multiple materials.

Ce croisement des méthodes d’analyse consolide les résultats et évite les erreurs d’interprétation : il ne s’agit pas seulement de dater une matière, mais bien de comprendre quand et comment l’objet a pris sa forme actuelle.

Découvrez notre article à ce sujet : Pourquoi croiser plusieurs méthodes de datation en archéologie ?

Olivier Bobin

Olivier holds a master’s degree in chemistry (1996) and a Ph.D. in Archaeomaterials Physics (2001) from the University of Bordeaux. In 2005, he co-founded the CIRAM laboratory with Richard Chéret, and today serves as its co-director and scientific director.

Dans le cadre des études archéologiques, une datation carbone 14 brute ne suffit pas à établir une chronologie fiable. La calibration chronologique transforme les résultats bruts en dates calendaires exploitables. Elle améliore aussi leur interprétation grâce à des courbes de calibration reconnues et à un protocole analytique rigoureux.

Pourquoi la calibration est indispensable

Évaluer l’âge des vestiges ne consiste pas seulement à choisir une méthode de datation. Il faut aussi tenir compte de la nature des matériaux, des objectifs de la fouille et de l’intégration des résultats dans une chronologie cohérente.

Overview of archaeological dating methods: between relative and absolute dating

Les méthodes de datation se répartissent en deux grandes catégories complémentaires. La datation relative, qui est fondée sur la stratigraphie, la typochronologie ou la sériation, permet de positionner un artefact dans une séquence sans en déterminer l’âge exact. Elle reste essentielle pour interpréter les contextes. Cependant, les archéologues la complètent souvent par une datation absolue afin d’affiner leurs hypothèses.

Parmi les techniques absolues, la datation carbone 14 (ou radiocarbone) est la plus utilisée pour les matériaux organiques comme les os, le bois, les graines ou les textiles. Elle nécessite toutefois une calibration chronologique afin de convertir les âges radiocarbone en années calendaires. D’autres méthodes complètent cette approche, notamment la dendrochronologie, la thermoluminescence (TL) et l’OSL.

Le choix de la méthode dépend du matériau étudié, de son état de conservation, du contexte de fouille et de la précision recherchée. L’accompagnement d’un laboratoire spécialisé permet d’orienter ce choix dès le début du projet.

The challenges of a reliable chronology for archaeological interpretation

Une chronologie fiable permet de comprendre les dynamiques d’occupation, les séquences constructives et les interactions humaines. La datation brute, obtenue après l’analyse, ne suffit pas : seule une datation calibrée permet d’insérer un événement dans une grille chronologique exploitable archéologiquement.

La précision d’une datation dépend de la qualité de l’échantillon, du prélèvement, de la méthode utilisée et de la calibration. Les courbes IntCal corrigent les variations naturelles du carbone 14 et améliorent ainsi la fiabilité des résultats.

Dès le début du projet, un laboratoire spécialisé comme CIRAM aide à garantir la cohérence des datations. Il limite également les biais liés au prélèvement ou au choix de la méthode.

Chronological calibration: central to the adjustment of absolute dates

All radiocarbon dating needs to be calibrated before it can be used archaeologically. This operation, still sometimes underestimated, directly conditions the accuracy and reliability of chronologies.

Why calibrate radiocarbon dating? Calibration principles and curves

Carbon 14 has never been present in constant quantities in the atmosphere. Natural variations in C14 levels over time distort the raw results, expressed in BP (Before Present) years. This is why it is essential to use a calibration curve to convert the raw radiocarbon age into reliable calibrated calendar dates.

Les courbes de calibration carbone 14 s’appuient notamment sur les cernes d’arbres, les coraux et certains sédiments. Elles convertissent les âges radiocarbone en dates calendaires et réduisent les incertitudes liées aux variations naturelles du carbone 14.

From theory to practice: protocols, limits and interpretation of calibrated results

Il est essentiel de suivre un protocole de calibration-datation rigoureux dès la phase de prélèvement pour garantir la qualité de la calibration chronologique. Plusieurs facteurs peuvent fausser l’analyse. Un mauvais échantillonnage, une contamination ou un choix de méthode inadapté peuvent compromettre le résultat, même avec une courbe de calibration fiable.

Par ailleurs, toute interprétation d’une courbe de calibration carbone 14 nécessite une expertise : les plateaux de la courbe peuvent générer des plages chronologiques étendues, et l’intégration statistique (modèles bayésiens, par exemple) peut s’avérer nécessaire pour affiner les résultats. Il est également possible de croiser plusieurs méthodes afin de renforcer la fiabilité des résultats. Cette approche est d’ailleurs recommandée dans les contextes chrono-stratigraphiques les plus complexes.

Finally, it is crucial to identify the limits of calibration curves as a function of period and location. The support of a laboratory specializing in archaeometry enables you to navigate with precision in this demanding technical field, which is in constant need of improvement.

Specialized laboratories and best practices for reliable calibrated dating

The effectiveness of dating and calibration methods depends as much on the quality of the analysis as on the dialogue between archaeologists and the laboratory. Close collaboration is essential to secure the entire dating chain.

The importance of specialized laboratories for calibration and interpretation of results

Faire appel à un laboratoire spécialisé ne constitue pas une simple étape technique. Ce choix permet de construire une chronologie plus robuste et plus facilement exploitable. Dès la phase de fouille, un partenaire comme CIRAM peut intervenir pour conseiller sur la stratégie de prélèvement, identifier la méthode de datation archéologique la plus adaptée à la nature des vestiges (os, bois, mortier, matériaux organiques, briques, sédiments).

Un laboratoire comme CIRAM ne se limite pas à produire une datation. Il interprète également les résultats, explique les dates calibrées et accompagne les archéologues dans leur analyse. Cette approche experte évite les erreurs fréquentes comme une calibration mal paramétrée ou une lecture erronée des courbes de calibration.

Since calibration protocols are sometimes specific to different materials, it is strongly recommended to establish a collaboration plan as soon as the first surveys are carried out. This also enables you to anticipate the time and costs associated with the analysis.

Best practices and advice for archaeologists: selection, deadlines and integration of results

To ensure the reliability of chronological calibration methods, several best practices must be observed:

• Sélectionner des échantillons non contaminés et représentatifs du contexte étudié,
• Documenter précisément la provenance stratigraphique,
• Transmettre toutes les données utiles au laboratoire (datation relative, typologie, séquence).

Once the dates have been obtained and calibrated, it is essential to integrate them into the overall chronology of the operation. This means working to ensure consistency with field data and, ideally, support from the laboratory to avoid misinterpretation and optimize scientific output.

La calibration chronologique est donc une étape incontournable pour garantir la fiabilité des datation carbone 14. Une méthode adaptée, un protocole d’échantillonnage rigoureux et une calibration réalisée à l’aide d’une courbe de référence permettent d’établir une chronologie fiable et exploitable.

Patrick Rossetti

Patrick is the director of the Archaeology Department at CIRAM laboratory. He coordinates projects involving dating, isotopic analysis, and the characterization of archaeological materials, in collaboration with research institutions, museums, and archaeologists in France and abroad (ORCID: 0000-0001-8770-6732).

The atmospheric nuclear tests conducted in the 1950s and 1960s profoundly altered the amount of carbon-14 in the atmosphere. This increase, known as the “post-bomb effect” or “bomb peak,” now serves as a particularly valuable chronological marker for dating recent organic materials.

In the field of art and cultural heritage, this isotopic signature makes it possible to identify materials produced after 1954, detect certain restorations, and even uncover recent forgeries.

In this article, we explain how the post-bomb effect works, the materials involved, the measurement methods used, and practical applications for authenticating works of art.

How does the post-bomb effect work?

Why did nuclear tests alter carbon-14?

The atmospheric nuclear tests conducted between the 1950s and 1960s profoundly altered the concentration of carbon-14 in the atmosphere. This sudden increase produced a very distinctive radiocarbon curve, known as the “bomb peak” or post-bomb effect.

Beginning in 1954, nuclear explosions led to massive production of carbon-14. Its concentration peaked in 1963–1964, before gradually declining as a result of exchange with the oceans and the biosphere. This trend now serves as a particularly precise chronological marker for dating recent organic materials.

Two factors influence the concentration of carbon-14 in the atmosphere:

• The Suess Effect: The burning of fossil fuels, which contain no carbon-14, gradually dilutes its concentration in the atmosphere.
• The post-bomb effect: Atmospheric nuclear tests, on the other hand, caused a rapid increase in carbon-14, with a peak observed between 1963 and 1964.

Unlike conventional carbon-14 dating, whose accuracy is limited to recent periods, the post-bomb signal makes it possible to date certain organic materials with an accuracy of up to one to two years between 1954 and 2020. This level of precision is particularly useful for identifying materials that are inconsistent with a work’s stated date. Thus, the post-bomb effect makes it possible to:

• Determine whether a material predates or postdates 1954;
• Verify the chronological consistency of a work attributed to the 1950s through the 1970s;
• Distinguish between antique ivory and ivory from a more recent harvest.

What materials can be dated using the post-bomb effect?

The post-bomb effect applies only to organic materials that incorporated atmospheric carbon after 1954. It is used in particular to date:

Carbon-14 dating analyzes only the sample taken. It does not directly date the object as a whole. A canvas may be later than the painting it supports, just as a stretcher may have been replaced during restoration.

What are the limitations of this method?

Like any scientific method, post-blast analysis has certain limitations and requires caution in interpretation.

Carbon-14 dating applies only to the sample taken. Dating a canvas is not the same as dating the painting itself, just as dating a piece of wood does not allow us to directly date a sculpture.

Restorations are also a potential source of contamination. Adhesives, varnishes, or consolidants can alter the measured signal if they are not removed before analysis. This is why laboratories implement preparation protocols tailored to each material, such as the extraction of alpha-cellulose for plant fibers or the purification of collagen for bone and ivory.

Finally, some materials may have been reused. Although rare, it is possible that old wood was used in a more recent work. In such cases, carbon-14 dating must be supplemented by other methods, such as dendrochronology, xylology, scientific imaging, or provenance analysis.

Each object therefore requires an appropriate sampling strategy to ensure that the results can be interpreted reliably.

How do we measure the post-bomb effect?

The AMS method: the gold standard for measuring carbon-14

Accelerator mass spectrometry (AMS) is the gold standard method for post-bomb dating in art. It directly measures the ratios of carbon isotopes ¹⁴C, ¹³C, and ¹²C with excellent sensitivity using microquantities (discrete samples that are not visible after analysis).

The AMS method makes it possible to analyze extremely small quantities of material, sometimes as little as a few milligrams. It can be applied to plant fibers as well as wood, paper, and ivory. The results are expressed as percent Modern Carbon (pMC) and then converted into a chronological range using post-bomb calibration curves.

The analysis consists of five steps:

1. Targeted sampling (masked areas, edges, excess wire)
   
2. Pretreatment: mild/strong solvents depending on matrix, alpha-cellulose extraction (fibers/paper), collagen purification (bone/ivory), varnish/glue removal.
   
3. Graphitization to isolate pure carbon
   
4. AMS measurement with isotope correction via δ¹³C
   
5. Interpretation based on the post-bomb reference framework (North or South) and preparation of a documented scientific report.

How should the results be interpreted?

After an AMS measurement, the results do not correspond directly to a specific date. They must be compared to post-bomb calibration curves, which are based on changes in atmospheric carbon-14 levels since the 1950s. These reference curves make it possible to convert the measured amount of carbon-14 into a probable chronological date.

This step is essential for answering questions such as:

• Was the work created before or after 1954?
• Is the material consistent with the stated period of creation?
• Is it possible to tell the difference between an original piece and a more recent reproduction?

Specialized laboratories use calibration curves appropriate for the material’s hemisphere of origin (NH or SH), apply international standards, and interpret the results while taking into account the substrate being analyzed, its geographic origin, and its restoration history.

At CIRAM, this interpretation is based on calibration standards recognized by the scientific community, as well as on quality control protocols that ensure the reliability of the results.

The Aftermath of the Bomb and the Art Market

In the art market, the “post-bomb” effect addresses several issues related to expertise. In particular, it can be used to:

• Authentication of modern works: this can prove, for example, that a material actually dates from the 1960s-1970s.
  
• Detection of fakes or imitations: this identifies materials that are too recent to be consistent with the advertised attribution.
  
• Regulatory compliance (CITES): this differentiates pre-1975 ivory (legal) from more recent ivory (prohibited).
  
• Litigation or insurance: it is used to establish scientific proof that can be used in the event of a dispute or claim.

Here are a few examples of practical applications of post-bomb analysis in the field of art.

• 19th century" painting on canvas: with linen dating. If a bomb-pulse is detected, then the canvas is post-1954. We can therefore consider a replacement canvas, an apocryphal work, or a copy.
  
• Drawing on paper: the absence or presence of a post-bomb signal can validate or disqualify an alleged dating. This analysis is particularly useful in the case of contested archives or manuscripts.
  
• Assemblies, gluing, and marouflage: Cross-dating (of the support, lining, and adhesive) makes it possible to reconstruct the chronology of the interventions. This analysis is essential for insurance claims.

In the end, a post-bomb analysis transforms a doubt (stylistic incoherence, incomplete provenance, contentious signatures) into an objective scientific element that can be understood by a committee, a court or an auction house.

Olivier Bobin

Olivier holds a master’s degree in chemistry (1996) and a Ph.D. in Archaeomaterials Physics (2001) from the University of Bordeaux. In 2005, he co-founded the CIRAM laboratory with Richard Chéret, and today serves as its co-director and scientific director.