Ajanta: Conservation of Murals
Culture plays a vital role in the development of any nation as it
represents values, goals, practices and attitudes. Art and culture manifest
themselves in almost all economic and sociological manners. A country as
diverse as India is a perfect example of culture. India has one of the world’s
largest collections of folk songs, dance, theatre, literature and painting.
India has a diverse culture, the most customs of which have been rooted in
texts and scriptures which date older than 500 BC and have been scientifically
approved. The Ajanta Caves is a perfect example of India’s heritage. The Ajanta Caves and temples stand around the Wangorah River in the Aurangabad district of Maharashtra. It is a horseshoe-shaped collection of rock-cut Buddhist cave temples which date back from 2nd century BCE to about 480 CE. The sculptures and the painting of the Ajanta caves are considered a masterpiece of Buddhist religious art. The caves also include the finest surviving examples of ancient Indian art, particularly expressive paintings and rock-cut sculptures that show emotions through gestures pose and form. The painting depicts the pictorial tales of the rebirth of Buddha. The Ajanta caves were hidden inside a jungle until accidentally they were discovered by a colonial British officer Captain John Smith in 1819 while he was on a tiger hunt. Until then, the vivid colours and mural wall paintings were abundant in Indian History. After its discovery, Ajanta attracted hoards of eager copiers, who tried hard to copy the paintings.
The walls of the caves essay extraordinary stories of the life of Buddha in
an elegant and graceful manner. Now, the murals of Ajanta are recognised as one of the greatest arts produced by humankind in any century. Up to the date, the picture gallery glows with the brilliant intensity of colours from any ancient civilization. Several physical and chemical conservation measures were carried out by the international and Indian conservators to evolve a suitable methodology for the conservation of painting and murals. In 1953, after taking over of Archaeological Survey of India (ASI), an expert panel for the preservation of the Ajanta Murals was set up. During the post-independence era, the Archaeological Survey of India took charge of Ajanta cave paintings with an aim to identify the techniques of painting. After several observations, it is now found that the grounds of mural paintings at Ajanta are composed of mud plaster prepared by mixing ferruginous earth, organic matters, rock grit and sand. Microscopic examinations of the paintings indicate that the smaller particles in the mud plaster are composed of clay, fine particles of silica and laterite. Whereas the chemical analysis found that the organic matter was mostly due to the presence of large quantities of vegetable fibres and paddy husk. Current Deputy Managing Director of Afcons Infrastructure Ltd, S Paramasivan examined that the layers of fine lime plaster were treated with dilute hydrochloric acid which dissolved the fine plaster with efflorescence along with carbon dioxide emission. S Paramasivan has generated a lot of information about the characteristics of mud plaster in the light of physical appearances and stability. Over the past decade, the analysis of pigment has drawn the attention of several restorers of mural paintings. The restorers tried to identify pigments used in lime plaster. After long research restorers found that painters of Ajanta used lime and white clay (kaolin) for white, carbon (soot) for black, yellow ochre for yellow, red ochre for red, gluconate or terraverte for green and lapis lazuli for blue. All the pigments including white, red, yellow and green are residual products of the volcanic rock. They are locally available except for Lapis Lazuli, which seems to have been imported, because of its absence in the neighbourhood. But there is no scientific data on the analysis of pigment samples from Ajanta-Ellora.
The pigment of the Ajanta paintings are found to be easy softened by water,
this shows the existence of a water-soluble binding medium in the paint layer.
After the introduction and usage of glue or gum as the binding medium in
some of the caves at Ajanta, few researchers say that the animal Glu was
probably employed for the purpose and also mentions the possibility of glue
and casein. The problems in the preservation of mural paintings can only be
solved by a systematic scientific study of materials and techniques employed in their execution but it can only be identified if the binding medium form is at a priority research at Ajanta. A problem with the layered structures is their
complexity and stratified constitution on which study of materials cannot be
attempted without isolating different layers. Only the micro-levels of such
painted layers are easier to examine. Their examination involves the preparation of sizeable numbers of cross-sections of the painted stucco. Later
M.S. Mathur employed a technique to study pigments used in the murals. He
successfully attempted a micro spot test on the polished surface. But the
conservators/restorers had to face a lot of criticism after the appearance of
chalkiness, as a result of pigments studies, the pigments on Murals began to blur. It was a matter of great challenge to the chemists to explain the appearance of chalkiness on the cleaned surfaces and hence an examination of paint samples under cross-section was felt necessary. For this purpose, a small paint sample from the cleaned portion was mounted in polyester resin and that cross-section was examined under the microscope. The pigments were found to be intact and the whiteness was found to be only a superficial deposit. Biological degradation of Murals at Ajanta Paintings at the Ajanta depicts the story of the early ages. But it is estimated that one-fourth of the paintings at the Ajanta cave are lost due to insects that live in the rough plaster of the painted surface. Due to organic matter present in the plaster, a silverfish called Lepsima Saccharina caused most of the damage to the paintings. Silver fishes live to a large extent on carbohydrates such as
starch and dextrin and are said to be able to digest certain forms of cellulose.
They also thrive on small amounts of proteins (from the dead insects) and gum or glue used as a binding medium in wall paintings. Interestingly, during the late 90s in France, a green infection was noticed on paintings which were caused by bacteria carried on the shoes and sweat of visitors. Continuation with the context in 1970, a question arose, whether such an infection also existed at Ajanta. To find out the answer, a preliminary survey of the air spore and bacterial infection at Ajanta/Ellora was conducted. It was found that
microorganisms develop on the paintings if there is high humidity, around
70%, and in the presence of organic materials, such as the vegetable fibres
present in the plaster. This is the reason why the paint layer is also not immune to biological attacks, as ochre and lampblack are severely attacked by
microorganisms. The binding medium gum/glue can easily succumb to the
action of biological agents. Dust and dirt collected on the paintings absorb
moisture and, in turn, they absorb microbiological spores. Bats excreta provide nutrients and a carrier for microorganisms. Results showed that fungal spores inside the caves varied and are more numerous than outside the cave. The spore types, such as Aspergillus, Curvalaria, Cladosporium, Ascosporous etc., are common in all the caves, which suggest some Ceprophilous fungi predominate in the decomposition of paintings. With vide fluctuations in the relative humidity and temperature in the cave, the painted plaster suffers most considerable degradation. Most of the time, the plaster loses its rock surface and the pigment itself dries up and gets peeled off. But the degradation of plaster and paint layer was slow and progressive through the centuries, as they remained exposed to an unfavourable environment for the last 1500–2000 years. The colour developed a tendency to flake off and the paint layer became friable and powdery, due to its alteration, decomposition and the disappearance of the organic binding medium. Right from the discovery of Ajanta, the development of conservation methodology and improvement of techniques helped in the conservation of the murals in the caves. Today, in order to build any new conservation measures; it is imperative to know the past work for better plans regarding future intervention.
Every painting at Ajanta holds its own story and the murals of Ajanta are
recognised as one of the greatest arts. Their preservation and conservation have been a major concern by now which has been worked upon but better plans are needed.
