〔報文〕画絹の物性に及ぼす断面形状・殺蛹方法の影響―大和文華館所蔵作品調査データ含めて―

The present study aims to clarify the differences of traditional painting silk and commercial painting silk from the cross-sectional point of view. Traditional silk which was made by hand-reeling method had thinner cross-section than commercial silk which was made by auto-reeling machine on the results of scanning electron microscope observation. It also showed loose fibroin bunch as compared with commercial silk which showed thick fibroin bundle. It is suggested that this difference influences the degree of transparency on the painting silk based on digital microscope observation, especially in the case of reverse paintings. On the accelerating test with UV, moist heating method and electron irradiation methods, traditional silk showed lower color changes than commercial silk, and the result was presumed to occur by influence of the pupa killing method. Drying cocoon as commercial method, salted cocoon as traditional method and raw cocoon were tested by UVand moist heating accelerating ageing. Salted cocoon showed lowest change of tensile strength as a result. The present study also reports about the measuring data of the width and height of silk thread which was used in 4 paintings in the collection of Yamato Bunkakan. Silk thread prepared in Song dynasty showed wide cross-section, and Japanese silk thread showed thin cross-section than contemporary commercial silk.