Studio series: Natural dyeing with Black walnuts 2

Scouring water: Before & After; Photo © Karen Thiessen, 2013

If you are new to dyeing fabrics and wonder about the importance of scouring fabrics before committing them to the dye pot, here's a visual of all the gunk that is in them in the above photograph. Washing fabrics in the washing machine is not enough: all the fabrics that I scoured were pre-washed. Fabrics contain oils, waxes, sizing, and finishes, from the manufacturing process and during transit they encounter more chemicals to prevent mold and mildew and insect infestations.

Scoured fabrics; Photo © Karen Thiessen, 2013

Scouring removes the oils, waxes, and other chemicals so that the dyes can evenly penetrate the fibres. I boiled cotton and linen fabrics in a mixture of washing soda (sodium carbonate) and Synthrapol in water for two hours. Apparently you aren't supposed to use an aluminum pot with sodium carbonate because the combo reacts badly, but I did and the world did not end.

Soaking loose black walnut hulls; Photo © Karen Thiessen, 2013

I started dyeing my scoured fabrics in the black walnut dye liquor (with rain water) and in a few days I'll see how it all worked out. Since starting the process I learned a few things. First: the green hulls of black walnuts yield a deeper dye than the brown hulls. Second: because black walnut hulls are high in tannins process the hulls/nuts below the boiling point (maximum 88ºC or 190ºF) if you want a warm, rich brown. Higher temperatures extract too much tannin and yields a dull dark brown (from Karen Casselman's Craft of the Dyer, page 64). Unfortunately I boiled the first soaked walnut hulls for 2 hours. I use aluminum pots for dyeing.

I've started soaking a second batch (11 pounds worth) of black walnut hulls in tap water with a little vinegar. I'll let this soak a week before I heat process it at the lower temperature of less than 190ºF.

Natural dye books; Photo credit: Karen Thiessen, 2013

These are my two dye books that I am using for reference. I discovered Craft of the Dyer when I was a NSCAD student. It's a great book, but I found that I had to read here, there, and everywhere to get enough information about dyeing with black walnut hulls.