don't know about starch but I know they can be ironed if they get too wrinkled. Just set iron onto 'wool' setting and they will be good as new. I just make sure I bag mine in cello bags without wrinkling and send out to shops. How they look after them once received if down to them really I think. Thats sounds harsh but no matter how much you try they always wrinkle a bit.
not much help really