It has been a while since I have experimented with natural dyeing. I had a head of purple cabbage in the freezer, just waiting to be used. I finally took it out, let it defrost in an old container, added a little water, and let it be for about a day.
Before this, I prepped unbleached natural cotton fabric in an alum bath and let it dry completely. Then I wrapped it up, not really caring what pattern it would form, dunked it in cabbage and let it stay in the fridge for a day or two.
I decided to make a basic top with it and I am very happy with the results.