The Online Guild's Vegetable Dyeing Challenge offered several options, including things like doing comparisons, or working with fibers and/or dyes new to you. Both the cotton and the Procion MX dyes are definitely new to me, so they are a good choice for me to work with.
Cotton lint is actually ginned cotton, i.e. the seeds have been removed. However, it still contains bits of husk and bits of stems. And even though it looks and feels clean, it is not.
The directions that came in my dyeing kit (which can be found here), did not include instructions for washing the fiber, so I used the instructions given in the challenge notes.
These called for 1/4 teaspoon of washing soda (also known as soda ash or sodium carbonate) and 1/4 teaspoon of Synthrapol per gallon of water. Since I don't have any Synthrapol, I used my old standby, Dawn dishwashing detergent.
I weighted out 8 ounces (228 grams) of cotton and put it into my dedicated dye pot along with four gallons of water. That meant I needed one teaspoon each of washing soda and Dawn.
After it had simmered for about an hour, it looked like this.
Even though the cotton hadn't looked dirty, the color of the wash water tells a different story.
After rinsing, I divided it into four plastic bags to await color. That will give me roughly two ounces of fiber per color. When I want to do more, I'll wash some more cotton.
How much of a difference did the washing make? Well, can you tell which side was washed and which one wasn't?
The best part of doing this in my little dye "studio" was being able to keep the heat and humidity outside!
1st Procion MX Dye Experiments
2nd Procion MX Dye Experiments