by Bobbin.Threadbare » Wed Oct 23, 2013 6:04 pm
You know I'm not sure - I don't think it has anything to do with copper though. Natural indigo usually has a red cast, but I was shown some that had green recently and was told that the dying method influences the final look.
It's a desirable thing these days, but there's a tribe (Black Hmong) that I went to see in northern vietnam who HATE it. They repeatedly dip their fabrics in indigo, sometimes for up to a year, to get the fabric as black as possible -- and a reflective cast is their no.1 enemy.