IISER, helped by Kolkata art gallery, develops tech that can certify artworks without touching them

KOLKATA: Researchers from IISER Kolkata, working with an art gallery in the city, have created a non-invasive, Raman spectroscopy-based authentication method to detect fake paintings, an innovation hailed as a significant development for the art world.

The technique, dubbed RaFiTech (Raman Fingerprint Technology), is one of the most advanced art-forensics innovations from India and has secured seven patents.

For decades, authenticating a painting meant scraping off microscopic samples of pigment for chemical testing — a destructive process dealers often avoided and collectors rarely permitted.

RaFiTech replaces that with a laser-based, touch-free technique that reads the molecular signature of pigments, offering a scientific pathway to confirm whether a work of art indeed belongs to the artist it is attributed to.

The initiative was driven by Prakash Kejriwal, an art connoisseur and owner of Kolkata’s Chitrakoot Art Gallery, who long felt frustrated by the art market’s dependence on subjective judgments.

“If provenance is weak or a work comes through a dealer, authentication often rests on opinion or family certification,” Kejriwal said. “If the certifier isn’t deeply familiar with the artist’s work, uncertainty creeps in. This has damaged connoisseurship and trust in the art world. We needed an objective method.”

RaFiTech offers that objectivity. According to Soumyajit Roy, who leads EFAML Materials Science Centre at IISER Kolkata and is part of the RaFiTech project, Raman spectroscopy can distinguish pigments used decades or even centuries apart.

“In the case of Ganesh Pyne, for example, we detected pigments that are extremely old or prohibitively costly — materials a forger would never use. We also identified newer pigments that appeared on the artist’s palettes only during his active years,” Roy explained.

This dual fingerprint is impossible to copy. And the best part — the painting is never touched (during the authentication process).”

The team’s patented methods now allow authentication of works by Rabindranath Tagore, Abanindranath Tagore, Nandalal Bose, Jamini Roy, Ganesh Pyne, and even sculptures of Somnath Hore.

Curator Prabhas Kejriwal, who frequently manages exhibitions of Bengal masters, said the absence of a formal certification authority long plagued the industry. “Authenticity has always rested on provenance trails, expert opinions and stylistic assessments. These are useful, but not foolproof. RaFiTech finally gives us a scientific, unbiased method,” he said.

During the authentication, a narrow laser beam is directed at selected points on a painting. The pigment molecules scatter this light in unique patterns — known as Raman wave numbers — that act like a chemical fingerprint. These signatures — chemical fingerprints — are then matched with global pigment databases documenting when specific colours were manufactured and used. If the pigments correspond to materials available during the artist’s lifetime, the work gains credibility. If not, it raises immediate red flags.

Trisha Chakraborty, an IISER researcher leading the Raman-based pigment identification project at the RaFiTech Lab, said the method goes beyond single paintings. “We can compare pigment profiles across multiple works attributed to the same artist. If two paintings don’t share key pigment signatures, at least one is inauthentic.”



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