Abstract
This study investigates the methods of the natural dyeing of silk fabrics with Machilus thunbergii cortex extract. After the dyeing of silk with a Machilus thunbergii cortex extract, the dyeability of the Machilus thunbergii cortex extract was evaluated with the dyeing time, concentration, temperature, the numbers of repeated dyeing, the pH of the dyebath, the changes of the K/S value, and surface colors by the methods of mordanting and color fastness. The effective dyeing conditions with silk fabrics were at a concentration of 120g/L, the dyeing temperature at $80^{\circ}C$, and the dyeing time for one hour ten minutes. The effective number of repeated dyeing was three times. The dyeing operation was carried out in a neutral dyebath of pH 7. The K/S value was higher in most of the pre-mordants (except the Sn mordant) and a high K/S value was shown in the copper pre-mordant. The colors of the silk fabrics with Machilus thunbergii cortex were of various brown shades. The color difference was distinct when using the Fe-mordant and the colorfastness of all the dyed samples was low; however, the dry cleaning fastness was excellent at the 4-5 grade.