raw silk fibers from native thai silkworms, b. mori var. nangnoi sisaket-1, kindly provided by the queen sirikit institute of sericulture, thailand, were subjected to removal of the sericin by the method described by meesilpa et al. (2002). the degummed silk fibers were irradiated by a gamma irradiator (gammacell 220 excel, mds nordian) at the thailand institute of nuclear technology.