FEEDBACK FRIDAY: This Week in Natural Dye Questions

This week: the power of iron, dyeing with liquid dyes and can you dye synthetics with natural dyes?

Every week, we are emailed with questions from our natural dye community asking simple and complex questions that we thought might be worth sharing. Of course, all of your burning questions are answered by natural dyer in chief, Kathy Hattori, Founder of Botanical Colors.

I’m curious about the ferrous sulfate you have for sale. I’ve just started to learn about creating indigo vats, and am confused about the types of iron available out there. Some have a 20% iron content (perhaps agricultural grade?) and others indicate 99%. Can you tell me what the percentage of iron is in your iron?

The iron we sell is 99%. It appears as if the 20% variety is used in gardening. With all iron preparations, please observe safe use practices, especially among children and pets as it is unsafe for them. Keep it tightly sealed and out of reach of small hands or curious puppies.

Shop iron here.

I really love your work and concepts for dyeing. I’m hoping to buy some of your liquid dyes in the UK where I am based. I’ve been reading the instructions you provide on the web pages on how to dye using them and wondered what quantities/weight of yarn these instructions are for? I’m guessing you have to adjust the amount/% of liquid dye used according to weight of yarn. 

All of our dye recipes are based on the weight of dry fiber, referred to as wof.  Therefore, you can use any weight of fiber and multiply that weight by the percentages called for in the recipe.  For example, if you have 250 grams of fiber and the percentage weight of fiber is 6%, then you would multiply 250 x .08 = 15 grams.  Your local stockist (DT Crafts and Supply) can also provide guidance on the use of the dyes.

Shop liquid dyes here.

I recently used way too much alum potassium sulfate on cashmere and predictably, it has a gummy feel. Can I remedy this – remove the excess and return a comfortable “feel” to the shawl?

If you feeling this “gumminess” in the dried fiber, it’s difficult to say what might work to restore the fibers. Cream of tartar is used on wool to help protect the fiber cuticle, so it may be possible to use cream of tartar, but it also may not be effective as an afterbath.

Shop cream of tartar here.

I have been trying to research and am kind of coming up with nothing. Is there a way to dye synthetic fibers such as polyester or nylon with natural dyes? You guys are so helpful and love your blog! Looking forward to dyeing with your help!

The short answer is no for polyester. Nylon is more successful as it is a very old synthetic, developed in the 1930s, so the inventor was trying to give it the attributes of a natural fiber, as it was a replacement for silk fibers. If you want to try nylon, mordant with aluminum sulfate (treat it like a protein fiber) and see what your experiments result.

Shop aluminum sulfate here.