This study surveys the traditional methods of preparing the background layer of gilded Buddhist sculptures, and how they have developed over time. The finish of gilding closely depends not only on the mastery of the technique itself but also on the smoothness of the surface underneath. Therefore, the background layer is prepared in several stages, starting from the core, the base layer that supplement the natural roughness of the core, the hemp cloth layer for sturdiness, and the filling layer to even out the gaps, and finally the lacquer layer, more smooth and convenient for adhesives used for gilding. T raditionally, lacquer sap, similar to the substance used for lacquerware, was valued as the background material for Buddhist sculptures. However, recent scientific researches have revealed that celadonite, generally used for decorating dancheong, was also employed. In the 20th century, the introduction of new materials such as putty and plaster, new technique of spray painting, and gilding by craftsmen of other areas, has affected the traditional composition of background layer. This has simplified the gilding process for Buddhist sculptures, making it economically more efficient and faster, and bringing big changes to the Buddhist sculptures.