community of dyers

The "flower" on an indigo vat is the accumulation of bubbles on the top. You remove this so that you don't get it on your fabric when you dip it. You replace it afterwards because it does contain some indigo, so that you don't weaken the indigo vat for your next use.

The reason why you want to remove the "flower" before dipping is that the bubbles contain air, so they contain oxygen, which oxidizes indigo back from the soluble yellow form to the insoluble blue form. You want to dip your fabric in a nicely uniform dye bath, instead of having some parts of fabric affected differently by the bubbles and the oxidized indigo associated with them.

Maggie, I don't think you should worry about having lost the flower. If the vat is too blue, add more thiourea dioxide or sodium hydrosulfite; if the color is too weak, add more pre-reduced indigo.

-Paula

I've always wanted to learn about indigo dyeing but it seems like an intimidating process!

Judi Hurwitt
Approachable Art
http://approachable-art.blogspot.com

Thank you, Paula. Of course that makes perfect sense. I just couldn't quite push my mind there. My vat, I decided, was too blue, although there is no crocking on the things I dyed in it. So I started messing around and now it's kind of...dark olive. Not clear. I feel like an alchemist. It got gray and watery, so I just added more of everything. It really perked up colorwise, but then it was too dark again, so I added a little more thiox. Now it's a little dark, but getting a bit more green than blue. Still not clear, though.