It has pinked seams rather than the later serged, which points to a 'close woven' fabric like rayon for a rayon satin(ette) mix - so probably pre-nylon days. Okay, couture lingerie seams are still pinked to this day but it all certainly points to late 30's early 40's, as others have said. They were often bespoke at that time so having no labels wasn't so unusual. Looks lovely. Jealous - grrrrr!