Using Natural Indigo Paste
Q: Can I use your natural indigo paste for block printing on fabric or for use with stencils on fabric?
A: Natural indigo paste is a pigment but it needs a binder in order to adhere to fabric. If you were to apply it directly from the bottle to your fabric it would result in a temporary stain but then just wash right off. For the indigo to actually transfer and adhere to your fabric it must undergo a chemical transformation. Traditionally this is done by creating what is called a vat. You can find a wealth of information about creating a vat here: https://www.grahamkeegan.com/indigo-vat-basics.
Since natural indigo paste cannot be applied directly to fabric as a dye, pattern making is done by using resist on the fabric to keep the indigo from adhering to certain sections when you dip it into the dye vat. You can find some information about that specific process here: https://www.grahamkeegan.com/stencils-and-rice-paste.