Each week, we are emailed with questions from our natural dye community asking simple and complex questions that we thought might be worth sharing. Here are a handful from this week answered by natural dyer in chief, Kathy Hattori, Founder of Botanical Colors:
After using the 1-2-3 indigo dye vat, do you need to mordant the now blue skein before you overdye with yellow to get green or madder to get purple?
If you are overdyeing with a dye that does not require a mordant (like walnut hulls, for example), then you do not need to mordant after indigo dipping. However, if you are using a natural dye that requires a mordant (like weld or fustic or madder), then you should mordant your fiber for best results.
How is scouring different than washing fabrics?
Scouring is the term that means to remove all sizing, starches or oils that are part of the manufacturing process. If you have fibers that are called “greige” or “gray goods”, this means that all the finishes from manufacturing are still on the fiber and it may not dye as deeply or evenly if it remains unscoured. If you purchase “Ready for Dye” or “Prepared for Dye” fibers, then your scour process will be less intensive as these fibers have already had the manufacturing finishes removed. Follow this link for a “How to” on proper scouring.
I keep hearing from friends that I should use henna to deepen my indigo. Does it really make indigo a deeper blue?
Henna is often used in North Africa to create organic indigo vats. It serves the same function as fructose and in our experience, creates a very rich and deep blue shade that lasts and lasts. For best results, we create our stock solution, substituting henna for fructose, then let the solution and vat ripen for a day or two. We find that ripening seems to create a very rich and deep shade. If you don’t have much time, heating the vat gently will also help speed up the reaction among the ingredients. We like to use henna to create our indigo stock solution and then rebalance the vat with fructose.