Tuesday, April 22, 2008

Oil used in ancient Buddhist cave paintings at Bamiyan

Bamiyan is known for the idiotic destruction of spectacular statues by the Taliban in 2001. Behind the statues there are caves that have paintings dating back to the 7th century. But the cool thing is that some of these paintings used oil - well before the previously established date for the technique:
In many European history and art books, oil painting is said to have started in the 15th century in Europe. But scientists from the National Research Institute for Cultural Properties in Tokyo (Japan), the Centre of Research and Restoration of the French Museums-CNRS (France), the Getty Conservation Institute (United States) and the ESRF have recently identified drying oils in some of the samples they studied from the Bamiyan caves. Painted in the mid-7th century A.D., the murals show scenes with Buddhas in vermilion robes sitting cross-legged amid palm leaves and mythical creatures. The scientists discovered that 12 out of the 50 caves were painted with oil painting technique, using perhaps walnut and poppy seed drying oils.
And they found this through synchrotron spectroscopy (and here is the Wiki entry on Synchrotron - and check out applications):

A combination of synchrotron techniques such as infrared micro-spectroscopy, micro X-ray fluorescence, micro X-ray absorption spectroscopy or micro X-ray diffraction was crucial for the outcome of the work. "On one hand, the paintings are arranged as superposition of multiple layers, which can be very thin. The micrometric beam provided by synchrotron sources was hence essential to analyze separately each of these layers. On the other hand, these paintings are made with inorganic pigments mixed in organic binders, so we needed different techniques to get the full picture" Marine Cotte, a research scientist at CNRS and an ESRF scientific collaborator explains.

The results showed a high diversity of pigments as well as binders and the scientists identified original ingredients and alteration compounds. Apart from oil-based paint layers, some of the layers were made of natural resins, proteins, gums, and, in some cases, a resinous, varnish-like layer. Protein-based material can indicate the use of hide glue or egg. Within the various pigments, the scientists found a high use of lead whites. These lead carbonates were often used, since Antiquity up to modern times, not only in paintings but also in cosmetics as face whiteners.

But who did the paintings?
The paintings are probably the work of artists who traveled on the Silk Road, the ancient trade route between China, across Central Asia's desert to the West. However, there are very few studies about this region.
Read the full story here.