FEEDBACK FRIDAY: This Week in Natural Dye Questions

This week: Why your indigo smells weird and can Aquarelle dyes be used in bath and body products?

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:

I recently ordered some indigo dye from your company and also from another company in Belgium. Both of these indigo powders have a smell of mothballs or something similar, and both are organic and GOTS certified. I also ordered some indigo powder from another company that is not organic or GOTS certified and it does not have the smell. I was wondering if you had any information about indigo smelling and what could be the cause?

Thanks for your email. If you ordered from another supplier and it is instant indigo, or pre-reduced indigo, then that is synthetic indigo. I’m not sure what that smells like. If you are talking about natural indigo, I think the difference in smells is that many indigo manufacturers ferment their indigo in open pits from fresh leaves, and it smells a lot like manure or rotting vegetable matter (which is what it essentially is when it ferments). It can also be lighter, sometimes gray in color, and more granular.

Other manufacturers work with dried leaf indigo, and use a different extraction process, so it’s definitely going to smell different. Our indigo is also purified, so a lot of the excess vegetable matter is filtered out, leaving a stronger indigo powder that is more consistent. Since the grade I purchase is used in large scale natural dyeing, having a uniform product is really important.

Would your “How-To” tutorials work on fabrics as well?

Yes, the scour, mordant and immersion dye procedures work for all fibers: washed raw, fabric, yarn, felt and garments. Keep in mind that raw fibers can be contained in net bags or mesh to keep them in order and yarns should be cross-tied so they don’t tangle in the dye pot.

Can the Aquarelle Liquid Natural Dyes be used to color other substances, bath and body products? 

It’s a little confusing but the bottom line is that none of our dyes are certified for use in cosmetics, which requires a level of purification that textile dyes don’t inherently have. If you wanted to work with something that would withstand cosmetic manufacturing, you would be looking for pigments. The basic difference is that a dye is soluble in water and a pigment is not so the pigment retains its color and is more resistant to the color change brought on by using acids, oils, bases or other common cosmetic ingredients. Indigo powder is a pigment (insoluble in water) which is why some soapmakers purchase it for coloring their soap products.