There are many things to consider and understand when preparing fibers for natural dye. Here, I am providing a simplified overview of my process, but there are many other ways that you could approach this process.
MAIWA is the source of these procedures and a great resource to learn more about the process.
Choosing Your Material
Plant-based materials: Cotton, linen, hemp, etc.
Animal-based materials: Silk, wool, & hairs
Plant-based materials will require three steps: Clean, tannin, & mordant.
Animal-based materials will require two steps: Clean & mordant.
Cleaning
Plant-based materials
Fill a large pot with enough water to cover your material and allow it to move freely.
Add 2 tsp Synthropol & 20 grams of soda ash for every 450 grams of material.
Simmer for 1 hr and allow the material to cool in the water.
Rinse.
Animal-based materials
Fill a large pot with enough water to cover your material and allow it to move freely.
Add 5 mL orvus paste for every 450 grams of material.
Simmer for 1 hr and allow the material to cool in the water.
Animal-based materials should be heated and cooled slowly, not agitated by too much stirring.
Rinse.
Tannin
Plant-based materials only.
Fill your pot with fresh hot water.
Add 10 percent of the weight of the fiber of ground oak gall. If adding 100 grams of fiber, add 10 g oak gall.
Stir to dissolve.
Add your wet material and soak for several hours. I typically leave mine overnight.
Gently rinse and move on to the mordant step.
Mordant
Plant-based materials
Fill a pot with clean, hot water (140 degrees F).
Add 2 percent weight of the fiber of dissolved soda ash.
Add 15 percent of the weight of the fiber of Aluminum Potassium Sulfate
Add wet material and soak for 2 hours, keeping water warm.
Rinse well in cool water.
Hang to dry overnight.
Your material is now ready to dye.
Animal-based materials
Fill a pot with clean, hot water (140 degrees F).
Add 15 percent of the weight of the fiber of Aluminum Potassium Sulfate.
Add wet material and slowly bring the mixture to just below a simmer. Steam, but no bubbles.
Hold for 1 hour and allow the material to cool in the mordant bath.
Rinse well in cool water.
Store in a damp cloth for 1-2 days before drying.
Your material is now ready to dye.