Journal of Korea TAPPI ISSN:0253-3200(Print) 펄프종이기술

The coloring technique in traditional Buddhist paintings involves applying animal glue size to the base material and then mixing pigments with a binder to create diverse colors. The base materials used for these paintings include silk, hemp, cotton, and Hanji (traditional Korean paper). Among these, Hanji was widely utilized both as a base material for painting and as a backing paper for artworks made on silk, hemp, or cotton, making it the most commonly used material. Hanji is made from the bast fibers of paper mulberry and a natural dispersant called Dakpul. While it is a highly durable neutral paper, the Hanji used in Buddhist paintings undergoes degradation due to the adhesives and pigments applied to it. This study aimed to analyze the causes of damage to Hanji in traditional Buddhist paintings based on the types of pigments used. Samples were prepared by applying animal glue size to Hanji and coloring them with natural mineral pigments, including cinnabar (Jinsa), malachite (Seokrok), azurite (Seokcheong), orpiment (Seokhwang), and lead white (Yeonbaek). An accelerated aging test was conducted to evaluate the effects of various glue and alum mixing ratios during the sizing process, as well as the type of pigments, on the tensile strength of the paper. The tensile strength of glue-sized Hanji decreased with low glue content and high alum content. Conversely, the tensile strength increased with high glue content and low alum content. Pigmented Hanji generally exhibited higher tensile strength than did glue-sized Hanji alone, regardless of the glue-to-alum ratio. Among the pigmented samples, those colored with malachite and azurite showed poorer tensile strength compared to those colored with lead white, cinnabar, and orpiment, with higher rates of tensile strength reduction observed.