Revealed! How scientists determine the age of paintings without damaging the artwork

Illustration of how scientists determine the age of a painting (freepik)

YOGYAKARTA - Many people are curious about how scientists determine the age of paintings, especially ancient works that do not have clear historical records or a definite date of creation.

Interestingly, through a combination of chemistry, physics, and art history, researchers are able to scientifically estimate the age of a painting without damaging its artistic value. How?

Why is the age of a painting important?

The dating of paintings is not just about the year number. This information plays an important role in ensuring the authenticity of the work, assessing the suitability of the material with its historical period, and becoming the basis for museum conservation and documentation.

In the context of the art market, the age of a painting also determines the economic value and credibility of a work. In addition, determining the age helps uncover forgeries or attribution errors of artists that often occur in paintings that are hundreds of years old.

In order to better understand how the age of a painting is determined, reported by VOI from the CIRAM Lab and Chemical & Engineering News pages, here are some things you need to know:

Basic Principles for Determining the Age of Paintings

In practice, scientists do not only assess the artistic style. They examine physical materials such as canvas, wood, paper, pigments, and paint binding materials. This scientific approach allows for a more objective assessment than visual analysis alone.

Also read the article discussing Examples of Applied Art in Everyday Life and its Explanation

Well, one of the most important methods is radiocarbon dating (carbon-14), which measures the residual radioactive isotope of carbon-based materials.

How Scientists Determine the Age of Paintings by White Lead Pigments

There was a significant breakthrough coming from a study published in Analytical Chemistry in 2020. This study introduced a new technique for determining the age of paintings through lead white pigments, one of the oldest pigments that have been used since the Roman era.

When lead in paint is oxidized, it forms lead carbonate that locks in atmospheric carbon-14 levels at the time the painting was made. In theory, this makes it an ideal candidate for radiocarbon dating.

The problem is, the purest pigment samples are usually in the main part of the painting, so taking it risks damaging the work. The solution is to take a small sample from the edge of the canvas, even though this area is often mixed with other carbonates such as chalk.

Scientific Solution: Heating and Solvent Extraction

To overcome carbonate contamination, researcher Laura Hendriks developed a gradual heating method. Lead carbonate decomposes at a temperature of around 300°C, which is lower than other carbonates. By collecting carbon dioxide at a certain temperature, scientists can isolate the relevant carbon-14.

However, initial experiments showed inconsistent results. The reason is the fatty acids from the paint oil, especially in new paintings. The solution is to add a solvent extraction step to remove the fatty acids before burning. This step proved to validate the method on both old and new paintings.

This stage is also important because the painting could have been restored without documentation, which was done by adding materials with different carbon-14 content.

Challenges of Accuracy, the Role of Calibration, and Imaging Technology

Once the carbon-14 levels are measured, scientists match them to a calibration graph of historical atmospheric concentrations. For post-1950 paintings, ages can be determined to within one or two years of accuracy. But for older paintings, estimates are typically within the range of several decades.

Therefore, this method is very effective for detecting forgery, although it is less precise for determining the exact date of an ancient work whose age is unknown.

Institutions such as CIRAM complement dating with pigment, binder, and multispectral imaging techniques. Methods such as UV, infrared, X-ray, and grazing light allow scientists to see hidden layers, early sketches, to the traces of restoration.

It is this combination of dating, imaging, and chemical analysis that forms the most reliable approach to determining the age and authenticity of a painting.

The way scientists determine the age of a painting does not depend on a single method. A multidisciplinary approach ranging from radiocarbon, pigment analysis, to advanced imaging can be the key to uncovering the history, authenticity, and value of a work of art without damaging it.