really, really, really, thin

in this case use the wire fillament of a old cable, heat it but not too close or will melt, roll it under a ruler. i also tried to thin the strtched sprue using the polishing -grinding bit of the dremel, not too loose not too tight either, grind in all directions in a circular pattern this way one point is in contact at one time, any way it is so thin that could not tell if the wire is not THAT circular. results were good for me anyway.