Materials and techniques of Kandyan and southern schools of mural painting of Sri Lanka: Mid-eighteenth to late-nineteenth centuries.

摘要

Materials and techniques of the three schools of mural painting of Sri Lanka belonging to the late-historical period (mid-eighteenth to late nineteenth centuries) were studied. These three include the central Kandyan, provincial Kandyan, and southern maritime schools. The primary hypothesis was that visible stylistic and iconographic distinctions between these three schools will also be reflected in technological differences between them. A secondary hypothesis was that technological differences between schools will result in differences in observable state of deterioration or preservation of paintings, and that future treatment strategies may therefore need to differ. Samples of supports, grounds, primers, paints, and coatings from six randomly selected sites were examined using optical microscopy, scanning electron microscopy (SEM), x-ray spectrometry by energy dispersive microanalysis (SEM-EDX), microchemical methods, x-ray powder diffraction, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible absorption spectroscopy (UV-vis), thin-layer chromatography (TLC), and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS). It was found that paintings were done on a clay and sand ground covered by a white primer. The mineral huntite, clay, barium sulfate, lead white, gypsum, calcite, and lithopone were used for the primers or as the white pigment. Gums, drying oils, plant resins, and emulsions of those three materials were used as binders. Cinnabar or dry-process vermilion, orpiment, Prussian blue, manganese blue, and soot were used as pigments. It was found that there was control over the choice of materials within the central Kandyan school and less control within the southern maritime school. No uniformity was seen in the painting technology within the provincial Kandyan school. It was suggested that the differences in the nature of deterioration problems of the sites are related to the differences in the materials and techniques of painting at each site.