Iron vat problems:

Iron sulfate turned rusty-colored when I dissolved it in water and no reduction is happening in my vat.

A couple of things could have happened here. The Iron sulfate quickly decomposes when added to water to iron oxides (rust). If you dissolve the iron sulfate in too hot of water, this accelerates the decomposition.  If you wait too long to add the lime, the iron may already have decomposed as well.

If your vat still looks like a rusty mess after sitting sealed for a day, settle out the indigo and another sediment, and either start over with fresh iron sulfate using the sludge as your indigo source or add Rit color remover to reduce the indigo in a hydro vat. (Rit color remover recipe) The iron will stay insoluble in the hydro vat and you will be able to carefully pour off the reduced indigo solution.

My iron vat has turned (color)?


Add more iron sulfate, starting with 1 tsp and stirring carefully. Add more after 30 min-1 hour if the vat is not restored.


Your vat has oxidized. Add 1 tbsp lime and stir carefully.  If the vat is not restored after 30 min-1 h, add 1 tsp iron sulfate and 1 tbsp lime, stir, and wait 1 hour. If the vat is still blue, add a liter or two of boiling water, carefully to minimize the introduction of air. If the vat has still not recovered in an hour, it may be best to recover the sludge and use it to make a small Rit vat.


This is good! Dye away!

How do I substitute your indigo into my vat recipe?

If you know the purity of the indigo you are accustomed to using, use the following formula to calculate how much Stony Creek indigo you need:

(purity of old indigo)(mass of old indigo)=(purity of Stony creek indigo)(mass of Stony Creek indigo)

For example, if you are accustomed to using 30 grams of 80% synthetic indigo and you are trying to substitute in 25% pure Stony Creek indigo:


24g/.25=96 grams of Stony Creek indigo needed.

Paste may be substituted directly into recipes and used exactly as powder.

Is there a difference between the 25% and 40% indigo powder?

We have seen no difference in dyeing between the 25% and 40% indigo powder, once relative indigo concentration is accounted for.  Higher purity may be more convenient for experienced dyers/high volume users, and may give purer blues used as a pigment.

How do I use the madder and black walnut dye pastes?

These dye pastes may be used exactly as madder roots and black walnut hulls, but you can skip all extraction and fermentation steps. There are suggested recipes in the product description for every dye we sell, but there is plenty of room for creativity! People have sent us photos of beautiful works using these extract pastes in printing fabrics and loads of other uses.  We would love to see your results.

Our Iron Vat Recipe