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

The yellow pigments employed in traditional Dancheong have been documented as Seokjahwang, Seokwoonghwang, Donghwang, and Danghwang in the Yeonggeon Dogam Uigwe from the 17th to 20th centuries. Component analysis of the yellow pigment used in Dancheong within the palace during the 19th and 20th centuries confirmed the presence of arsenic sulfide compounds. National heritage restoration efforts should focus on accurately recreating artifacts using traditional techniques and materials historically employed. To effectively use orpiment, which was historically employed in Dancheong, for the restoration of national heritage, it is crucial to form a stable coloring layer by examining discoloration and determining appropriate concentration of glue solution in glue sizing treatment and binder. To evaluate the stability of the orpiment coloring layer, glue sizing treatment and Noerok-celadonite painting were first applied to the samples, followed by coloring with orpiment, malachite, and lead white at binder concentrations of 3.0%, 6.0%, and 9.0%, respectively. The samples were then subjected to accelerated aging and outdoor exposure tests. Orpiment, characterized by a wide particle size distribution and a finely layered structure with numerous voids, exhibited a higher ratio of pigment to glue solution compared to malachite and lead white. With a higher concentration of the glue solution in the glue sizing treatment, the pores in the wood surface were more effectively filled, resulting in a more stable coloring layer formed on top. However, increasing the amount of alum in the glue-alum sizing solution led to poorer color fastness, whereas a higher concentration of glue solution in the binder resulted in improved color fastness. The glue film surrounding the orpiment particles initially demonstrated a preservation effect; however, during the wet-dry accelerated aging and outdoor exposure tests, the glue film deteriorated due to moisture, resulting in discoloration and flaking. In addition, lead sulfide (PbS) is suspected to have formed at the interface between the orpiment and lead white coloring surfaces, while copper sulfide (Cu₂S) is hypothesized to have developed at the interface between the orpiment and malachite coloring surfaces, potentially resulting in a dark brown discoloration. Under UV accelerated aging, the surface layer of the orpiment coloring degraded to a lighter color and showed the poorest color fastness. In contrast, the dry accelerated aging showed the best color fastness.