I've started dyeing my yarn to expand my craft. I went to a Fiber Fest several years ago and a lady was dyeing wool with Wilton Cake Icing Dye there. I liked that idea because you can use your kitchen pots safely and you don't have to worry about chemicals. And also being a "nature nut" and like being "green", I wanted to try dyeing with plants, roots and seeds.
I did use different pots instead of my kitchen ones when I did those. I only used vinegar to make the colors stay. I wanted to stay away from copper or iron for now. I thought the colors came out wonderfully and can't wait till I knit with these!
The items I used for the yarn above was Madder Root, Wilton Cake Icing Dye (golden yellow) and light wash of black walnuts, Annatto seeds, brown icing dye with a wash of black walnuts. The last picture is black walnuts, one with full strength of the nuts and then the exhausted dye bath.