I've been washing and rinsing and drying and washing and rinsing etc many times some of my new purchased fabrics for the last few days. All 100% cotton, some dark green, some are red and it sounds like yours. All were purchased in a QS and expensive too. Vinegar, salt, hot water, cold water, nothing works. I wish I'd live by a river. I would put it in there and let the water runs 24hours a day loll... Isn't it frustrating!
I'll try to iron it. It is the only thing I have not tried. As far as finding Retayne around here I have not. I guess I'll have to order it online.
My SIL has been a quilter for over 20 years and she never had that issue.
Why is this happening to me *snif, snif* loll