There are 120 surviving gwaebul. Their known production began in the seventeenth century and continued until 1945. The grand scale of gwaebul paintings limits their transportation and makes them broadly inaccessible to the general public. For these reasons, the NRICH and Sungbo Research Institute of Cultural Heritage have been jointly performing a detailed survey of large-scale Buddhist paintings since 2015. They highlighted the academic and artistic significance of gwaebul paintings and obtained basic data for scientific conservation and restoration. In order to better conserve and restore gwaebul, it is important to investigate how they were produced and what kinds of materials were used. To this end, the NRICH and Sungbo Research Institute of Cultural Heritage are examining the materials employed to produce gwaebul using non-destructive analysis methods that minimize the damage involved. The coloring materials are largely divided between pigments and dyes. Pigments are substances that are undissolved by organic solvents, oil, resin, or water, whereas dyes are dissolved in water or organic solvents. The examination of coloring materials involves identifying the overall preservation and surface conditions and selecting analysis sites for each color, including areas that have been repaired or where paint is flaking. Using a portable microscope, the gwaebul were examined to identify the forms and sizes of the pigment particles and the coloring conditions (the use of single or mixed pigments). The analysis of the main components of pigments was conducted using a portable X-ray fluorescence spectrometer. The color differences in single and mixed pigments were measured through a spectrophotometer. Organic pigments (particularly indigo blue and black ink), which are not detected with the portable X-ray fluorescence spectrometer, were analyzed using an ultraviolet-visible spectrophotometer.

▶ Coloring Materials Used in Large-scale Buddhist Paintings