Characterization of mural painting pigments from the Thubchen Lakhang temple in Lo Manthang, Nepal

Abstract

Very few publications are available on materials and techniques used by ancient Nepalese artists to paint mural decorations. This paper presents the first results of scientific examination aimed at characterizing the composition of the pigments present in paint samples collected from the south and east wall decorations of the 15th century Thubchen Lakhang monastery located in Lo Manthang, upper Mustang, Nepal, The temple was built in rammed mud and wood by order of King bKra.shis.mgon in 1470 and completed by 1472. Cross-sections of the 14 collected samples were prepared and the pigment composition was analysed stratigraphically. The same samples were also investigated, without preparation, for surface pigment characterization. The first results of the micro-Raman analyses showed that different blue pigments were used, sometimes alone, as in the case of azurite, and sometimes in combination with lazurite. The red and orange paint layers are constituted of orpiment and vermilion, both alone and in combination. A very interesting gilding technique that makes use as mordant of pararealgar with traces of orpiment and vermilion has been identified. Red ochre is present in the brown colour decorations. Malachite was used to paint the green decorations. Some samples also showed the presence of the copper sulfate hydrate brochantite, which may represent an alteration product of malachite. Further research will be needed in order to characterize the organic binding media composition that, in conjunction with these results, will guide restorers in the identification of the most appropriate restoration procedures to be adopted. Copyright © 2004 John Wiley & Sons, Ltd.