Using Radiocarbon Dating as an Authenticity Proof of a Work of Art

Corinne Chartrelle, expert in the fight against trafficking in cultural goods at École nationale supérieure de la police, tells us about the raising of a dating technique helpful in identifying forgeries.

In 2018, the Central Office for the Fight against illegal Trafficking in Cultural Goods (OCBC), an investigative service of the French Central Directorate of the Judicial Police (DCPJ), dismantled a network of traffickers, more precisely forgers, who were selling fake paintings on the art market. More than 250 paintings were seized at the time. For the first time, OCBC investigators called a team of French researchers from Saclay Laboratory to try to use radiocarbon dating on some of the paintings and prove counterfeit. 

The aim of the request was to know whether providing an accurate date of the works of art investigated was possible and whether the latter could match the period in which the artists were alive and thus able to create them. The scientific analysis is one of the methods used during investigations about authenticity.

The works have been carried out by Mrs Lucie Beck and published in April 2022 issue of the Forensic Science International journal. Mrs Beck admits that radiocarbon dating was little used in the art sphere due to its lack of accuracy.

“For periods from XIV to XIX centuries, we can date within a margin of fifty years, at best. For art historians, this is an information of little interest.”

However, everything changed when OCBC investigators asked whether paintings supposed to be earlier than Second World War couldn’t have been performed by the last decades’ forgers.

Why? Because the atomic bombs went through it.

Indeed, since 1945, year of bombing on Japanese towns’ Hiroshima and Nagasaki, further tests took place and this until 1963, when an agreement of partial prohibition of nuclear tests was signed across countries. Mrs Beck explains that a lot of 14C was produced during these open air tests, to the point that the concentration in the atmosphere doubled. This phenomenon is called “bombs peak” by researchers. According to 14C amount in a sample, a painting can thus be dated before or after 1950. In the case of the OCBC investigation, two paintings supposed to have been performed by two artists dead in the 1940s, Henri Martin and Blanche Hoschédé-Monet, were submitted to this scrutiny.

The analysis dealt with linen and wooden chassis samples, together with a hair from a brush stuck in the varnish. If no information came from the wood, probably because of a contemporary frame (ancient frames are frequently used by the forgers), fibres would have spoken. They came from plants that grew after 1950 and likely dating from the 2000s.

This experience highlighted that these paintings were not original works of art. 

Sources:

Pierre Barthélémy Journal le Monde 21/02/2022

Forensic Science International 7/02/2022

Author:

Corinne Chartrelle, ENSP