Dye Project: Weld Extract

For our final dye project this season we're using a commercial weld extract. Weld (Reseda luteola), also called dyer's weld, dyer's rocket, and dyer's weed, is found throughout the Mediterranean, Europe and North Africa. Weld grows as a weed by the side of roads and railroad grades. The yellow flowers and small green leaves produce beautiful shades of yellow.



This was my first experience using a commercial dye extract. Extracts are much faster to work with, since you skip the process of extracting the dye from the source material. I admit to missing that process, but the extract produced a wonderful fragrance, like a pot of herbal tea, which was satisfying.

Dyer's Weld (Reseda luteola) Photo from Ixitixel project

Weld extract

I'm continuing to use our white cotton dish towels, which have been scoured using Synthrapol and soda ash. I'm also using oak gallnut powder as the mordant, and a bath of alum and soda ash as a brightener. This combination works well, but adds two days to the process. With some advanced planning, the processes of scouring, steeping in the gallnut mordant, and soaking in the alum and soda bath could be done in advance, so that the fabric is ready to dye whenever you are.

Oak galls (or gallnuts)

Tannin mordant from gallnuts

I used our patio for my outdoor atelier, but this project could be done in the kitchen using the hood fan for ventilation. For safety use a face mask when measuring out the fine powders so there is no risk of inhalation, and use rubber gloves when working with soda ash, which is caustic.

Outdoor studio

I followed this basic process, based on instructions from The Handbook of  Natural Plant Dyes by Sasha Duerr.

• Day 1, soak fabric in water 
• Day 2, soak fabric in tannin from oak gallnut (steep for 8-24 hours)
• Day 3, soak fabric in alum and soda ash (steep for 4-8 hours)
• Day 4, dye fabric with weld extract (simmer for 30-45 minutes, then steep overnight)
• Day 5, rinse and air-dry fabric

For this project, temperature is important. For the best color results, the temperature of the alum and dye baths should be kept at a simmer that does not exceed 180 degrees F. (or 82 degrees C.). I used a candy thermometer to monitor the temperature, and added cool water to the bath to lower it as needed. Rotating the fabric in the dye bath periodically also helps regulate  temperature, and ensure the mordant, alum and soda ash, or dye is distributed evenly throughout the fibers of the fabric.

For best color, simmer at or below 180 degrees F. (or 82 degrees C.)

I ordered the weld extract from Maiwa in Vancouver, Canada, and used their instructions and information from Dharma Trading Company to figure out a good recipe (see The Maiwa Guide to Natural Dyes and Natural Dye Extract Kit (Instructions tab). For three cotton dish towels (WOF is 231 grams), use 9-14 grams (2-3 teaspoons) of powdered weld extract (WOF is 4-6%). I used 5% WOF:

12g weld extract  =  5% WOF

231g fabric              100% WOF

Dissolve weld extract in water

Add weld to dye bath

I prepared a paste of the weld extract and water, and added it to a pot of water, then brought it to a simmer (keeping it at or below 180 degrees. Next I added the pre-processed, wet dish towels to the dye bath. The towels simmered for 45 minutes, and then steeped in the dye bath overnight. 

Steep dish towels in dye bath

Rinse until the water runs clear

Hang dish towels to dry

The next day I rinsed towels until the water ran clear. I hung the towels to air dry, then ran them through the washing machine to set the color, then air dried again. I love the intense yellow color (although it would be fun to try to achieve a range of intensities in future projects). 

Preserve the dye for future projects

I preserved the excess dye in glass jars to use in future projects and labeled them. Weld can be used as an overdye with blue woad and indigo dyes, to achieve green. Stay tuned for more experiments in the seasons to come!