Anyway, getting back to the red cabbage. I had thought it would make a blue colour, but my batch turned out purple as you can see. I used rain water in a stainless pot with a dash of alum crystals for mordant. Although it's not blue, it is a beautiful dye colour.
I tested it out on silk. Funny tho', while the silk holds the colour well, after a couple of days in the jar the liquid colour fades, even in a dark place. And by god it gets really stinky. I'm too scared to take the lid off!
In search of the elusive blue, and for my next trick, I'm going to try dyeing with black beans, which you can still eat after you've used the soak water. My son tells me they make really good brownie....who would have thought?