The Indigo Ferrous Vat a.k.a. The Iron Vat

How to Create an Iron Vat for Beginners

Before I began working with natural indigo, I was a long time admirer of the deep indigo hue on fiber. Today, I am going to share with you my current favorite Natural Indigo Vat, that I feel is friendly to beginning indigo artists or even those of you who wish to explore Shibori patterns in an afternoon. First, a little background on how I came to use the Indigo Iron Vat.

As you may remember, I hosted my first ever Shibori workshop event mostly for friends. My friend Amelia and I, had discussed sharing our knowledge and skills to learn something like an art-form or craft in an afternoon. With my background and experience in art education, the idea of hosting a workshop, came to me organically. For the first class, I used a beginner's Indigo kit​available by Jacquard. I often keep this kit as a back-up for parties or events, although I have shifted to using a completely natural kit with no synthetic reduction agents (they can be quite smelly, so be sure to work in a well ventilated space or outdoors, if you prefer this first kit!- my kit includes a few additional shapes and uses and all natural recipe- read on down for all the details!) 

Next, I attended a block-printing workshop out in the high-desert, and to my surprise that day we dipped our textiles into a fructose vat, which I write about here. I set out working with the Fructose Vat for many months. I found it ideal for one time use over the course of an afternoon, I had more challenges when sealing off the vat to prevent oxidation or rebalancing the vat. Now, I enjoy working with the Ferrous Vat a.k.a. Iron Vat for long-term use! To my surprise one of my five gallon vats, has been fermenting an creating beautiful blues for quite a few months and I simply store it in the shade in my garden. Occasionally, I mix up additional stock to add more pigment to the vat. 

Indigo fructose vat on the coals

Iron Vat Recipe that works 

I synthesized this recipe from multiple sources, including my own trial and error. This recipe fills a five gallon container.

•  2 tbsp powdered indigo (1)
•  4  tbsp ferrous sulphate - iron (2)
•  6 tbsp lime (calcium hydroxide) (3)​

Occasionally, for a large group workshop, I make this vat a bit stronger doing a 3 tbsp of indigo, 6 tbsp of ferrous sulfate and 9 tbsp of lime.

Making the Copperas Vat: Lime, Iron, and Indigo

Start Using the Indigo Shibori Kit now

Indigo Iron Stock solution

1. To begin, wet out the indigo in a small container with warm water, not boiling. Using small marbles, shake the jar or container until the indigo itself is oxidized. This first step is an important one as it activates all of the indigo pigment. You will prepare the stock in a 1 qt jar as seen above. I use about 10 round pieces of jade, that I have on hand.
2. Add in about 2 cups of warm water, not boiling~ I have read that boiling water can damage the indigo itself.
3. Add your iron to the jar, stirring carefully.   
4. Next, adding warm water and lime to the stock. Add lime gradually to avoid clumping. You might notice that some lime stuck to the sides of my jar, although I added warm water and lime slowly stirring in combination. 
5. Later, I scrape the edges of my jar with a long stick- I use a wooden dowel or paint stir. 
Once you see a separation in the stock, you are ready to go! I then tip my indigo stock carefully into my 5 gallon bucket- pre-filled with warm water. Although, the iron vat is considered a cold water vat, I find that a little warm water helps start up the process. I stir in the stock, additionally I rinse and add any indigo still inside of the glass jar. Be careful not to over-stir the indigo vat, as you want to avoid introducing too much oxygen into the vat. You will see a coppery surface on the vat, along with a crusty looking blue indigo flower- this is known as the flower and the coppery scum. 

Recap of Iron Vat Supplies

Everything you need:

• Indigo, Iron, and Lime (get the Shibori Kit here)
• 1 qt jar
• ​glass marbles
• particulate respirator - remember to cover your face when working mixing all powders and pigments. 
• long wooden dowel or paint stir
• 5 gallon bucket 

Comparing the Iron and Fructose Vats

The fundamental difference for me, has been that my iron vat has outlasted my fructose vat, with little extra effort on my part. It is important to note that I store my iron vat tightly sealed in my garden in Los Angeles and it has been pretty warm up until November. I use my iron vat primarily for cotton and linen fibers. I have also tried it with a 70% cotton 30% silk blend scarf and it works well- not too stiff or scratchy. 

For both wool and silk, it is advisable to use the 123 Fructose Vat instead. If you wish to purchase a Shibori Kit and would like me to sub fructose for iron, contact me within 2 days of purchase and I will do so. If you would like to learn more in person, then please join me for a hands-on Indigo dye experience at Renegade Craft Los Angeles, where you will have the chance to do a "live dip" into the indigo vat to create a beautiful and reusable tote-bag. December 8th and 

Up next, I will share my recent experience and workshop where we used over-dyed madder with indigo for beautiful results!