Weld on Cellulose Yarns

I have not been hibernating, but I am woefully behind on sharing my dye news. So, my first post of 2012 is actually a belated one that I began writing weeks ago.

Back in December, I decided to dye several skeins of cellulose yarns (linen, cotton, and cottolin) for future projects featuring naturally dyed yarns. So many colors to choose from…. I have tons of dried weld in the closet, which made yellow an obvious choice. To prepare for dyeing with weld, I went back through my old dye notebooks, and found a note that one summer some of the weld plants bolted and flowered in their first year, but only got to be about 2 feet tall. So, weld can flower the first year, but technically it’s a biennial.  In my experience, the plants get giant (5-6 feet) in their second year, hence all the dried weld in the closet. Hence yellow yarn.

There are a range of opinions about how to achieve the best results with natural dyes on cellulose (i.e., plant) fibers. Everyone agrees that a thorough scouring is necessary to begin. I washed the skeins in hot water with regular laundry detergent first, then used soda ash at 2% weight of goods and an anionic scour from Earthues (ordered from the lovely and inspiring Nancy Zeller at Long Ridge Farm) at 6% WOG.

Some folks recommend an alum-tannin-alum sequence using aluminum sulfate and a tannin source. Others recommend just aluminum acetate with no tannin. I decided to follow instructions from Earthues (maybe not their most current recommendations) and treated the yarns with tannin first (Earthues’ gallotannin, from oak galls) at 5% WOG, then the next day mordanted with alum acetate at 5% WOG. My yarns were 22/2 unbleached cottlin and 20/2 linen half-bleach.

I used 9.36 oz. of dried weld (stems, leaves, and flowers) to make the dyebath, planning to dye about 12 oz. yarn.

Here I must digress for a moment. Back in December I checked out Anne Bliss’ sweet little book North American Dye Plants from the library. In her preface she acknowledges the support of her family in tolerating the “odoriferous stews” her research required. In our house we call the same phenomenon “stinky pots,” though “odoriferous stews” sounds much more grand. Weld is a stinky plant. The flowers are stinky in a good way. The rest of the plant is stinky in a stinky way. I don’t mind it so much because I have a high tolerance for the smells associated with natural dyes. But I try to spare my love the worst of the stenches by dyeing outside when the weather permits. Our neighbor’s cat loves all my smelly treasures, and we have many funny photos of him enjoying my fiber and dye experiments. Here’s one of Hansel luxuriating in the weld harvest of 2009.

OK, so stinky pots happen outside when weather permits. But since it was a rainy, albeit mild, December, the weld dyepot had to be indoors while it was heating (I brought up the temp to 180, held for an hour, then cooled overnight before straining). Fortunately it was not very smelly when I first heated it. Afterwards, it got outrageous! I did not extract the plant material multiple times, though some people recommend this. Once was enough.

With weld, many people recommend chalk to heighten the color, and/or dipping the fiber in an alkaline afterbath. I decided to add both calcium carbonate (at 3%WOG) and soda ash (at 2%WOG) to the strained dyebath before adding the skeins. The pH was between 9-10. I always do a delayed rinse, meaning I let the dyed yarns dry completely before rinsing them. I got intense, though kind of weird, color.weld-dyed skeins I would describe the linen skeins (on the left of the photo) as mustard. The cottolin (on the right) are a lighter greenish-yellow. I put a color wheel in the photo for comparison.

Weld has a reputation for yielding the most pure or “clear” yellow but you wouldn’t know it from this batch of yarn. I concluded that the tannin affected the color, and the fact that the fibers weren’t bleached also made a difference.

Seeing how intense the color was, I got overly ambitious and decided to use the exhaust bath to make green by overdyeing some cotton and cottolin skeins previously dyed blue with woad. This was my first attempt to make green with cellulose yarns (though I have made many successful greens on wool and alpaca by dyeing the fiber yellow first, then overdyeing with woad). Well, my results were really pathetic and disappointing. Here’s a photo comparing them to a woad dyed skein that I wisely did not mess with.woad overdyed with weld Sorry for the blur, but the colors are pretty accurate. The woad dyed skein is on the far right. They all started out that color. I treated them with the same tannin-alum sequence as the yellow skeins, thinking the tannin might create a nice teal. Sadly, no.

I attribute my lack of success to two factors. First, the weld bath must have been exhausted, and the very little color that was left attached unevenly to the fiber. Second, I must have had a chemistry problem, even though I was pretty sure I wouldn’t. The pH of the exhaust bath when I put the woad-dyed skeins was 8, which I didn’t think it was high enough to strip the blue off the yarn. But clearly it did.