FEEDBACK FRIDAY: This Week in Natural Dye Questions

Mysterious indigo

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’m an indigo dyer using an iron vat. I keep getting the lime/iron residue grains adhering to my fabric when I pull it out of the vat and it either creates spots like this (attached) or just makes a piece look inconsistent. Do you guys have any tips and/or forums you could point me to?

The iron should be dissolved before adding the other ingredients, so mix it with very hot water prior to adding it to the vat.  You will need a fair amount of water and should not see any iron grit in the bottom of your container when dissolving.

Do not let the fabrics sink to the bottom of the vat or stir them vigorously in the vat as it stirs up the sediment on the bottom of the vat.  Gently hold onto the fabric at all times.

You can also create a physical barrier between the bottom of the vat by taking a plastic colander and placing it upside down so it’s resting on the bottom of the vat.  Remember to remove it when stirring the vat.  Other dyers have used pasta pot inserts but I find the metal reacts with the iron vat.
Finally make a separate large tub or bucket of water, and immerse the goods in this water bath after you pull your fabric out of the vat. This helps remove any residue that might cause staining. Rinse and finish the piece after it is completely oxidized.

I just overdyed a scarf with indigo that I had originally mordanted with iron and alum and dyed with several natural dyes. I was expecting to get various red violets and purples but instead all of the colors were muted like they were dyed in grey. I am assuming the iron reacted in the indigo. Is it a bad idea to mordant dung-dye a fabric and then dip it in indigo?

It does sound like there was a secondary color reaction or possibly discharge happening with the mordants and the indigo vat. It’s not necessarily a bad idea to overdye colors in indigo, but the best way to get clear overdye colors when using indigo is to scour fabric, dye indigo, then mordant and overdye with natural dyes. It seems counter-intuitive, and you need to practice a bit to understand what depth of indigo blue will create what overdyed color, but it sharpens your color blending skills.