Vibrant Pigments, Global Exchange
Against a field of deep blue, sword‑bearing demons surge toward a sacred fire. Ram — yellow‑clad, rendered in blue — lets loose a rain of arrows, with Lakshmana steady at his side. Vermilion blood spills from the demons as the ritual tilts toward battle.
Demons Approaching Rama and Lakshmana at a Fire Ceremony (Homa), illustration from a Ramayana series, India, Rajasthan, 18th-19th century. Photo: © President and Fellows of Harvard College, courtesy Harvard Art Museums.
This 18th-19th century Rajasthani miniature, Demons Approaching Rama and Lakshmana at a Fire Ceremony, does not just capture a charged moment from the Ramayana where ritual and battle converge. It is a snapshot of global trade and cultural exchange in the 1800s.The dominant pigment in the painting is Prussian blue, synthesized in Berlin for the first time around 1706, manufactured across Europe and exported to Asia. In Japan, Hokusai used it to create The Great Wave (1831) – the iconic image that is a popular screensaver on digital devices today. The Indian yellow is a local pigment, once produced primarily in Bihar from the urine of cows that were fed only mango leaves. Before the British banned the production of Indian yellow, the pigment had made its way to Europe. In this Rajasthani painting, the Prussian blue and Indian yellow come together to create the dark green of the holy man’s sash and one of the demon’s shorts.
The chemical composition of the pigments used in this work and more than 200 other South Asian and Himalayan paintings and manuscript folios is now available at the click of a mouse, thanks to Harvard University’s Mapping Color in History initiative. Focusing on the materials and histories of South Asian art, its searchable database allows users — anyone, anywhere in the world with reliable internet access — to explore the paintings by title, pigment, keyword, date, region and more. The initiative, which began in 2018, is the product of a collaboration between conservators, computing specialists and art historians among others. The database offers a new way to read history – through color.
“The Great Wave”. Credit: Katsushika Hokusai, Public domain, via Wikimedia Commons.
It all began with a pigment puzzle. In 2016, a conservation scientist at a museum in Boston detected cobalt in a 15th-century Jain manuscript. But smalt, a cobalt-infused blue glass pigment, was manufactured in Europe and exported to Asia only from the 17th century. The assumption was that conservationists had retouched the color. It piqued the interest of Jinah Kim, professor of Indian and South Asian Art at Harvard University, who was gathering data on pigments as research for her book on the material history of Indian painting. Kim wondered, “Did everything have to come from Europe? What do we know about actual pigment usage in India at this time period?”
Katherine Eremin, Senior Conservation Scientist at Harvard Art Museums, cracked the cobalt pigment puzzle. Eremin narrowed down the origin of the glassy cobalt pigment using its geochemical signature – it had trace elements associated with a cobalt mine in Kashan in Iran. The deep-blue smalt pigment, assumed to be European, most likely originated in Asia. She also analyzed a 17th century Rajasthani painting in the Harvard collection and determined that it had smalt which originated in Europe.
A Nayika and Her Lover, page from a dispersed Rasamanjari (Blossom Cluster of Delight) series, India, Basohli, c. 1660-70. Credit: Harvard Art Museums/Arthur M Sackler Museum.Kim’s larger question remained: was there an indigenous system of colorants in India we know nothing about?
Long before synthetic hues, artists sourced their colours from a range of mineral pigments, plant-based dyes and insect-derived colorants. To identify and analyze these pigments is to understand the material core of art. Consider the color green in Indian miniatures. Is it a blend of blue and yellow pigments, as in Demons Approaching Rama and Lakshmana at a Fire Ceremony? Or is the green from beetle wings? If copper is detected in a painting, does this vibrant green come from malachite or atacamite? A suite of microscopy, imaging and spectroscopic techniques, which use light to decode the molecular composition of materials, allows researchers to determine the chemical makeup of pigments. Such detailed analyses can guide conservation strategies, inform restoration choices and help authenticate valuable paintings.
Past and present
What you cannot learn from a dead artist, or glean through an analysis of paintings using instruments, you can ask a living practitioner of traditional art, says Kim. Today’s artisans often rely on recipes and techniques passed down through centuries. There is value in understanding the process. This concept of artistic traditions being passed on from generation to generation is enshrined in The Intelligence of Tradition in Rajput Court Painting, by Molly Emma Aitken.
In 2021, conservator Anjali Jain, the India-based research manager of the Mapping Color in History team, visited the workshop of Babulal Marotia, an award-winning miniature painter based in Jaipur, to document this living tradition. Marotia says he chooses pigments based on color and tone. Mixing colorants with gum Arabic gives them a smooth, glossy finish that allows for fine layering. Marotia paints on handmade paper with an ultra-fine brush, no longer made of squirrel hair.
As a postdoctoral fellow at Harvard’s Straus Center, material scientist Celia Chari analyzed forty‑two colorants from Marotia’s palette. A little over half aligned with pigments found in 16th‑century manuscripts: yellow harital (arsenic sulfide), red hinglu (mercury sulfide), and kajal (lamp black). Others had slipped out of use: the gentle red of safflower; the translucent maroon of lac, once derived from Kerria lacca insects and traded in Europe as Indian Lake. Ultramarine — lajwarda, the mineral blue once prized for its depth — has largely vanished, replaced by plant‑based indigo. “Limited availability and changes in modern supply chains make it difficult, even financially unviable, to source the exact materials used historically,” Jain says.
Among contemporary pigments, Chari found Prussian blue — a Rajasthani staple for more than two centuries — alongside synthetic stand‑ins for Indian yellow, such as chrome yellow. She also identified white arsenolite, an inorganic compound undocumented in South Asian art, and brown barium ferrite, with no recorded use as a pigment in any culture. If the presence of arsenic or mercury raises concern, Chari notes that Marotia is fully aware of the toxicity and relies on thorough handwashing as protection. In the end, it is aesthetics — not chemistry — that guides his choices.
Through this pioneering study, which was published earlier this year, the researchers have just begun to explore the materials of contemporary South Asian artists through a scientific lens. Such studies can help future conservation efforts of contemporary paintings and deepen our understanding of traditional pigments. “It is all part of a continuum,” said Kim.
Better conservation
Because India holds most of the surviving paintings– in its various styles– these institutions become natural partners in tracing how pigments travelled through centuries and regions. Most museums in India don’t have in-house instrumentation – a notable exception is the Chhatrapati Shivaji Maharaj Vastu Sangrahalaya, Mumbai.
For most museums, transporting artwork to instrumentation centres is fraught with risk. To make the analytical techniques accessible on site, the Mapping Color in History established the Mobile Heritage Lab equipped with portable, handheld instruments. Already, the mobile lab has been deployed for the pigment analysis of old illustrated manuscripts at the Asiatic Society in Mumbai. Similar studies are underway at the Maharaja Sawai Man Singh II Museum in Jaipur’s City Palace. Discussions are in progress for a similar collaboration with the Government Museum and Art Gallery in Chandigarh, home to a collection of antique Pahari paintings.
“Sometimes old objects of art are treated with such absolute reverence – they’re left alone when, in fact, research-based conservation efforts would serve them better,” said Kim. As Project Director of Mapping Color in History, she emphasises the need for analytical studies to guide informed decisions about conservation. While conservation itself lies outside the scope of the Mapping Color in History project, the goal is to offer science-based insights to museum conservators – empowering them to make evidence-based choices that enhance the longevity of the works in their care.
The more researchers probe these pigments, the clearer it becomes that every brushstroke carries a record of the world that made it. The surprise is not that the colors endure — it’s how much they’ve been waiting to tell us.
Materiality between Art, Science, and Culture in the Viceroyalities (16th–18th Centuries) is a series of research seminars organized by the Universidad Nacional de San Martín in Argentina that is bringing together scholars to examine the artistic materials—everything from wood to feathers to animals and insects ground up to make pigment—used during this period in Latin America, what made them unique, and what they can tell us about the history of art and cultural exchange.
Goal: To rewrite colonial art history through the lens of materiality—foregrounding indigenous knowledge, ecological entanglements, and transatlantic exchanges.