mleku on Nostr: it's basically like batik but in reverse, you put the design as a negative using wax ...

it's basically like batik but in reverse, you put the design as a negative using wax and then soak it in bleach and the unwaxed parts are bleached

incidentally i'm not sure if she uses wax, there is a goop you can get for making screenprints that lets you use a projector and the parts of the material that are lit with light (has to be done in a darkroom) set into a substance that is water resistant and then with screen printing you can then push paint through the holes.

probably you can even do it just with some kind of photo-sensitive bleach substance that is relatively unreactive until you project light onto it

but i do think she does it with wax, hand-painting the wax around the areas that you want to be bleached and then covering the rest of the material with wax and the bleach will only attack the uncoated parts.