This recipe and technique is based off Graham Keegan’s no-boil black, which, according to Keegan, “is a riff on a portion of the 1734 French manuscript by M. de Beaulieu describing the process demonstrated to him by the Indian cotton painters of Pondicherry.”

The process results in deep, charcoal brushstrokes, thanks to the alchemical reaction between plant tannins (gallic acid) and iron (ferrous sulfate); their interaction is what the brushstrokes leave behind.

Many plants contain these tannins; it is the astringent quality found in tea and witch hazel, and may act as a natural pesticide and protection for the plant. Gallic acid is found in oak galls, oak bark, staghorn sumac, black walnut hulls, acorns, and more. When combined with iron, the tannins react and blacken; a discovery that lead to iron gall ink, the standard writing and drawing ink used in Europe from the 12th - 19th centuries.

Going even further back in time, iron was formed during the explosion that created the universe. It is found in earth’s crust and core, as well as plants, animals, and the blood that pumps through our bodies.

Ferrous sulfate can be ordered from dye suppliers like Botanical Colors. You can also create ferrous acetate, or iron oxide, by combining some rusty scraps of metal, white vinegar, and water. However, I’ve found using ferrous sulfate results in deeper, darker blacks and is easier to work with.

Fabric (cotton, linen, etc.) , scoured and soaked
Whole milk
Gallo tannin
Soda ash (washing soda)
Ferrous sulfate
White Vinegar
Guar gum

-Prep fabric first by thoroughly scouring in soda ash and hot water. Squeeze excess water from fabric.

-Combine a teaspoon of gallo tannin with a cup of milk using an immersion blender until no clumps remain and the tannin is fully incorporated into the milk. Use a large container for this as it will bubble and foam up quite a bit. Room temperature milk is a bit easier to blend and not as cold for the hands to work with as opposed to milk that's fresh out of the fridge. 

-Pour solution into a pot or bowl large enough to hold your fabric. Add fabric and thoroughly work solution into the fibers with your hands. Squeeze excess solution from fabric.

-Lay fabric flat to dry completely.

-At this point, you can move onto painting, or, dip your fabric in the milk/tannin solution for another round. I like the added dip as it results in darker brushstrokes. A single dip will yield grayish-purple brushstrokes. The additional dip also ensures the painting solution doesn’t bleed when applied as the proteins in the milk act as a binder. 

-Fabric can be prepared ahead of time and stored for later use. It’s best to have lots of fabric prepped on hand to paint, some for testing and experimenting, and some for the finished work. I usually spend a day or two prepping before getting ready to paint - I find it helpful to separate the creative process from the technical. 

-Once you’re ready to paint, lay your fabric on a flat surface (with some dropcloths underneath). Iron out any wrinkles and pin in place.

-To create the painting solution, add 5G of soda ash and 10G of ferrous sulfate to a large container. Carefully pour in 100G of white vinegar (it will bubble and foam up) and then add just shy of 1G of guar gum. Mix with an immersion blender until thoroughly combined. Once you’ve worked with this solution, you can play around and adjust the amount of guar gum to your liking. At this point, I like to let the solution rest and the bubbles dissolve, as it is easier to paint with. The painting solution will keep for about 24 -36 hours.

-Apply the painting solution to the fabric to create your designs. As the solution is applied, the brushstroke will change from almost invisible to brownish orange to purple to black. Keep the fabric taut and unwrinkled while applying. 

-Allow the fabric to dry completely before moving to avoid any unintended marks. Once dry, lay it flat for a day or two to cure. 

-Fill a washing machine with warm water and dissolve 1/4 cup of soda ash. Once the machine is full and the agitation cycle has started, quickly and carefully add the fabric in, making sure the entire piece is submerged and moving in the water. For this step (and smaller pieces), I’ve also used a 5gal bucket and a garden hose. For either machine or bucket, be sure the water is constantly moving, as this will help to avoid streaking and bleeding in the brushstrokes.

-For the last step, run the fabric through another wash cycle, this time adding a 1/4 cup of vinegar to the water. This pH change helps to shift the mark making lines from brown to grey/black.