Get out ye olde calculator and pencil, that's what. Following the directions given by the dye manufacturer for immersion dyeing using Procion MX dyes, I first figured out a factor to convert the quantities of materials used. They give all directions relative to 1lb. of dry fiber. I would only be using a *sacrifice* 50g skein of yarn.
So I went through the list and converted all the quantities as needed - but still there was a question tickling my brain.
This yarn is a mixed protein and cellulose. How was the dye going to react since each fiber needed different handling?
The Cellulose (Cotton) needed Alkaline (Soda Ash). The Protein (Cashmere) needed Acid (White Vinegar) AND Heat.
So I decided to Start the process with heat and a little acidity to welcome the Protein, then finish the session with alkaline and a cooled down temperature. There was no guarantee this would work - but what I've noticed and learned in my other dyeing attempts is that if I follow the basics, I have gotten great results. So I decided to just go for it.
I added the needed water to the pot and brought the temp of the liquid up over a flame. Usually with cotton, you would just use warm tap water. I watched the liquid closely so it was just giving off a little steam on the surface, not simmering, not boiling.
After I added the salt and mixed dye (1 part Raspberry; 2 parts Lilac; and 1 part Midnight Blue), I added a couple of tablespoons of vinegar, and mixed well. Then I added the yarn, reduced the gas flame as low as it would go and stirred constantly for 10 minutes. Then I turned the flame off and followed the manufacturer's instructions for the rest of the process (20 more minutes of constant stirring; remove fiber; add soda ash; repot fiber; stir every 5 minutes for another half hour) with one exception.
Big Difference: I added 1.5 times the amount of soda ash that was recommended to neutralize the acid of the vinegar. If I was dyeing a larger amount of fiber, I would make the percentage of the alkaline even higher.