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Lost Treasures of Tibet

Creating a Wall Painting:
Preserving History Inch by Inch
by Broughton Coburn

Lost Treasures of Tibet homepage

The summer of 2002 marked the fourth year of a five-year program to conserve and protect the Thubchen and Champa monasteries, artistic and religious centerpieces of the formerly forbidden kingdom of Mustang. For generations, these exquisite 15th-century Buddhist chapels or lhakhangs (literally "houses for divinities"), situated in Lo Monthang near Nepal's border with Tibet, have gone neglected, though the dry environment and the kingdom's very inaccessibility have provided some level of protection.

Circumstances are changing, however. Relatively recent environmental damage has threatened these monuments' 24-foot-high wall paintings, and the integrity of the structures themselves had been at risk. Without careful intervention, these monuments and their precious Tibetan Buddhist masterpieces would have been lost forever, a tragedy arguably akin to losing Michelangelo's frescoes in the Sistine Chapel.

A team of conservation experts—several Italians and a Guatemalan led by Englishman John Sanday—are now facing an enormous challenge. Centuries of soot and dust have obscured the serene faces of these images. More distressingly, over the past three decades, two of Thubchen monastery's soaring walls have suffered catastrophic "washdowns" as bursts of snowmelt, restrained by ice dams that formed on the roof, have drained into the building, scouring gullies and depositing streaks of mud across several wall paintings.

That's not all. Rising damp, a product of poor drainage outside the walls, infiltration, and stagnating water inside, had caused erosion from the floor up. Ground level outside many of the walls was found to rest well above the floor level of the prayer hall, partly as a result of accumulated debris from the collapse long ago (likely due to earthquake) of what might have been an upper story or clerestory.

The conservators found sections of some paintings hanging like curtains.

Capillary action has drawn water from the wetter exterior of the structure toward the drier inside, saturating the earthen walls and their layers of clay. This moisture, along with soluble salts that recrystallize and expand as they dry, has collected behind the relatively impermeable paint layers and pushed against the painted surface from the inside out. The result: scaling and flaking of the preparatory paint layers, or renders, and in some cases their detachment from the walls altogether. Indeed, the conservators found sections of some paintings hanging like curtains.

The immediate objective of the ongoing conservation work has been to replace the ailing roofs and superstructure of these large chapels and to restore the underpinning—and brilliance—of the wall paintings. To do that, the conservators and their local trainees had to first stabilize the building and then rebuild the wall surfaces' traditional foundation layers of clay.

Made of mud, strong of stone

The original walls of Thubchen and Champa lhakhangs were made of rammed mud mortar (gyang in Tibetan), which workers tamped into wooden frames in a process similar to the laying of cement foundations, though the mud mortar is of thicker consistency and the work far more labor-intensive. Instead of massive foundation frames reaching the full height of the walls, medieval Lobas—as the people of Mustang are known—used sectional wood frames of about five feet in height, lifting and placing them atop successive layers as they dried.

The clay used for these walls (shi sa) was crude, containing wood fragments, pebbles, and other foreign material. The walls are stronger than one might expect given the nature of these materials, which gain part of their strength from their sheer mass. (In some cases they are more than three feet thick at the base.) Some later walls were constructed of large, sun-baked adobe bricks bonded by a finer clay mortar.

Sanday's conservators did not intend to restore areas where painted images had flaked or eroded away, but in some cases they needed to rebuild and prepare sections of walls for painting or line drawing. The Raja, or King, of Mustang and the townspeople of Lo Monthang stressed that they wanted to worship entire, not incomplete divinities. It was agreed that, in order to meet international restoration standards while accommodating the wishes of the local people, some of the lost areas would be plastered and painted, to form linkages and continuity across small gaps. More expansive lost areas, often the lower portions, were completed only as line drawings without color fill, however, in order to restore the functional integrity of the paintings without attempting a "restoration."

Layer by layer

The techniques and materials the conservators now employ are virtually identical to those used over 500 years ago. (Thubchen was completed in 1472, Champa in 1448.) To begin flattening the surface of the wall, workers—relying on experience rather than precise measurements—mixed a blend of chopped straw, slightly sieved shi sa clay, and a slurry of cow dung (primarily as a binder). They then flung handfuls of this admixture onto the wall and worked it in with a smearing motion. When it had partially dried, they applied two or three additional, generally thinner, layers.

Even after all this work, the preparation of the wall had scarcely begun. In a report following the first year of restoration, chief conservator Rodolfo Lujan described the extraordinarily diverse ingredients needed to fashion the paintable surface:

"The next (second) layer is composed of river sand and small pebbles mixed with a yellowish clay (pimbo) found at the west of Lo Monthang. The third layer consists of very fine sand (chema) mixed with pimbo and a greenish-brown clay known as shi pi pema, which comes from Jag Dha Mountain, north of Lo Monthang. A fourth layer is composed of shi pi pema and ghi sa, a light beige clay from Ahma Loun Mountain, southeast of the city. The final priming layer, on which artisans applied the preparatory drawing (in black paint) and the paint layers, consists of a mixture of khsa (an extremely fine white clay) with animal glue (ping) and local chang or beer. After drying, this was carefully polished."

Only after this multilayered surface was ready did the anonymous masters of medieval Mustang begin painting.

Renaissance artists in Europe sometimes relied on a technique, known as secco, that is roughly analagous to the Tibetan one.

Interestingly, when creating their own wall paintings, Renaissance artists in Europe sometimes relied on a technique, known as secco, that is roughly analagous to the above-described Tibetan one. Secco paintings, among them Leonardo's Last Supper, were painted onto a dry, polished, lime-based render (made from inorganic binders such as lime, mud, and gypsum) and a primer. Frescoes, on the other hand, including Michelangelo's in the Sistine Chapel, were painted onto moist ("fresh") lime-based render.

Origin of the pigments

The deep blues and greens as well as the paler shades of these colors come largely from azurite and malachite, basic carbonates of copper that generally occur together and sometimes blend within the same rock. Tibetan painting scholars David and Janice Jackson report that these minerals were largely mined in Nyemothang, in central Tibet. They were crushed into a sand, wrapped in small leather bags, and sold to painters by the Tibetan government.

The painters in turn prepared their azurite and malachite in a lengthy scrubbing and rinsing process, before grinding it in water. They did not have to do much grinding to obtain the much-desired rich blues and greens. Finer grinding resulted in paler shades, however, meaning that the artists could obtain full ranges of value by separating the particles on the basis of their size. In some cases, blue and sometimes green was mixed with varnish, making it brighter and more translucent.

The mineral cinnabar—or native mercury sulfide, the ore from which mercury is produced—was the source of the deep vermilion color, and it came mainly from Hunan province in China. Over 1,800 years ago, Chinese alchemists learned to separate and recombine the mercury and the sulfur, forming vermilion, which when powdered produced the desired deep red crystals. This was traded widely throughout Asia, and some of the cinnabar and vermilion used in Mustang and Tibet likely came from China by way of India. Many of the flower details in Thubchen's paintings were refinished in careful brushstrokes of red lac, a kind of natural shellac.

The Jacksons found that black and the inks used for writing and woodblock prints were carbon-based, generally soot or charcoal, while white came from chalk (calcium carbonate), lime (calcium oxide), or bone and bone ash. Orpiment yellow, which in the case of Mustang may have come largely from hot springs in eastern Tibet, is a trisulfide of arsenic, while the less intense yellow ochre, used primarily as an undercoat for gold, is a variety of the mineral limonite.

Using the hues

When commissioning a painting, patrons of religious art would generally budget for gold separately from the rest of the painting. Much of the gold was obtained, as it continues to be today, from Newar merchants in Lhasa, Tibet's capital. (The Newar ethnic group, renowned for its exquisite craftsmen, constitutes the original inhabitants of the Kathmandu valley; some Newar merchants settled in Tibet, where many intermarried with Tibetans.)

In Thubchen, the paintings were gilded with gold powder spread on with a brush and pen nib, especially for the flesh of the Buddha. Gold leaf, however, was used to highlight the raised areas, which were created a pastiglia for the deities' jewelry and other ornamentation. In addition to gold's intense, reflective luster and its tendency to remain untarnished, artists found it easy to work with.

Each color also contains inherent symbolism, which is especially meaningful in the creation of tantric mandalas, the circular representations of the universe done in paint or sand:

Blue/black = wrath, pollution
Red = love, attachment, power
Yellow = ascendance, riches
White = peace, purity

Perhaps surprisingly, many of the minerals from which pigments are derived had medicinal value in the Tibetan system of ayurvedic medicine.

Despite the existence of modern materials and techniques that might be suitable for rebuilding and restoring ancient Tibetan monuments, there are several reasons why conservators study and use methods that were employed centuries ago. First, the original materials are locally available, often from their original sources; artists can collect clays and soils from the same sites their forbears gathered them from over half a millenium ago. Second, the early methods are not necessarily inferior to their modern substitutes, as evidenced by their longevity. Finally, some of the traditional wall-building, plastering, and painting techniques, which have been perfected over countless generations, are still in use today. So local artisans can be employed with some confidence in the resulting quality, though the relearning curve has been steep.

Eleventh-hour aid

These conservation efforts—funded by the American Himalayan Foundation and overseen by Nepal's King Mahendra Trust for Nature Conservation and the Annapurna Conservation Area Project—are occurring none too soon. Ever since Nepalese authorities opened Mustang to tourism in 1992, Lobas have been emigrating in increasing numbers to Kathmandu and the cities of south Asia in search of their fortunes. Even those who are religiously inclined now seek higher Buddhist instruction in Kathmandu and India. They are leaving behind something of a cultural and economic vacuum.

Lobas now compete for the chance to become conservation trainees.

In Lo Monthang, when Sanday and Lujan originally proposed hiring local people to assist them in the conservation and cleaning work, they were met with skepticism and apathy, despite the Raja's endorsement of their efforts. But the magic of time and dedication and a few modern techniques have brought renewed glory to Thubchen monastery, and with it the attention, respect, and revived faith of the town's citizens. Women's groups now use the Thubchen chapel for their meetings, townspeople proudly escort tourists through the building, and even the abbot of the town's newer monastery is keen to rededicate Thubchen as an active religious center.

Most impressively, local Lobas now compete for the chance to become conservation trainees, and nearly as many women as men have joined the ranks. Indeed, the most rewarding result of this conservation project may be the trained and motivated residents. They now have many of the skills needed to begin replicating this work elsewhere in Mustang and across the southern slopes of the Nepal Himalaya, the native architecture of which has been neglected for decades and in some cases centuries. A revitalization of indigenous traditions, religious belief, and community pride has been an unexpected side effect of this heart-warming project on the roof of the world.

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Sakyamuni Buddha

In a recently restored painting inside Thubchen monastery, Shakyamuni Buddha gazes down on visitors, his face a picture of wisdom, serenity, and compassion.

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Repairable washdown

The "washdown" streaking the right side of this painting is repairable. Sadly, the portions at the bottom lost to rising damp are not.

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Workers on roof

Lobas work to repair the roof of Thubchen monastery in the summer of 2001.

New wall

To create a new painting surface, two Lobas mix straw, clay, and moistened cow dung while their companions smear this formula onto a wall in Lo Monthang.


An array of prepared colors before him, an artist uses a mortar and pestle to grind mineral into yellow pigment.

Closeup - gold

This artist is using gold pigment, made from gold brought south out of Tibet, to enhance the raised surfaces in his painting.

Assembly hall

As this photograph shot within Thubchen's soaring chapel reveals, the conservation team arrived just in time. A few more years of neglect, and these masterpieces of medieval Tibetan art might have vanished.

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Further Reading

Jackson, David P. and Jackson, Janice A., Tibetan Thangka Painting: Methods and Materials. New York: Snow Lion Publications, 1984.

Sanday, John, "The Gateway to Nirvana: Conserving the Temples of Mustang," Orientations, October 1999.

Lost Treasures of Tibet Web Site Content
Before and After

Before and After
Watch centuries of grime vanish from nine stunning paintings.

Creating a Wall Painting

Creating a Wall Painting
Conservationists and locals revive Mustang's artistic traditions.

Tour Mustang

Tour Mustang
Journey through this hidden Tibetan kingdom in northwest Nepal.

Deciphering Buddha Imagery

Deciphering Buddha Imagery
What you need to know to recognize an image of Buddha.

Broughton Coburn Broughton Coburn has lived in the Himalaya for two of the past three decades, working in wildlife conservation, protected-areas management, and development. He is the author of five books and in 1997 was granted the American Alpine Club's Literary Achievement Award for his body of work.

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