Tuesday, October 1, 2013

Indigo Vat Party, and Sharpening The Synthetic Vat

On Saturday, I had a few friends over to play with indigo. I provided the space, food, reference books, whatever equipment I had lying around, and some clothes lines; Lesley brought synthetic indigo stock solutions and her equipment; and everyone brought their own fabric, clothing, and yarn to dye. Deanna also brought three of her students in a high-school fashion course. It was so much fun!!

Fresh vat of white indigo. 

Tara dip-dyed this wool roving. Yum.
Works in progress.
Deanna and Audrey with a fresh vat.
Trish and Tara with another fresh vat.
I've read that dyers in Africa would have clients choose which tint of indigo was desired by looking at the sky.
Trish folded this one in triangles and clamped with chopsticks and wooden shapes from the craft store. So crisp!
Works in progress between dips.
Deanna is ombre dyeing a pair of white jeans. The orange bucket makes it much harder to see the colour of the dye vat.
Love how the lace didn't take up the dye much on Deanna's t-shirt with the diagonal pattern of rocks tied in. 
My ombre-dyed t-shirt in progress. This is done by dip-dyeing, but it's very tricky the get a line at the top that looks good if you're just holding the shirt between your fingers; I ended up doing a final dip of the entire t-shirt the next day.
Bev is dip-dyeing a white oxford shirt. I adore that green as the leuco-indigo starts to oxidize in the air.
Bev's accordion-pleated-and-clamped piece. Gorgeous! As you can see, by this time we were losing the light.
Oh dear, there are indigo drops on my camera lens. Anthony (one of Deanna's students) is dyeing a t-shirt.
Tara had tied these (flash-lit) hanks of wool yarn with wide elastics while they were still twisted into skeins.
Kitchen party!
Anthony's finished t-shirt. Somehow I missed getting photos of the other students' projects. 
When everyone had gone, I threw a pair of jeans into one of the remaining vats so I could exhaust it, and covered the other. The next day it was still well-reduced, so I did a bunch more dyeing with my daughter - mostly additional dips of projects I had started during the party, to see how dark I could get them to go. It worked beautifully to colour the cotton, even though the vat was stone cold, but I think using it cold wasted a lot of the dye - the pieces from this vat lost a lot of intensity when I rinsed them, and the rinse water was dark, dark blue.

The remaining works-in-progress the next morning in the rain.
I threw some white cotton binding in to make sure the bath was exhausted, and as you can see it took up next to nothing.
Audrey's first project. She is so excited by this that she has asked me to buy only white clothes for dyeing from now on.
After a day away from home, I returned to use the remaining vat (which had been covered since the previous night) on Sunday evening.
I tore up a white queen-size cotton bedsheet to play with.
Works in progress. I'm trying to get these super dark.
My ombre-dyed tshirt after its final dip. This is ramie, not cotton.
Yesterday, I decided to see if I could revive the vats, knowing that all redox reactions are reversible under the right conditions. There are some references for how to do it at these links - it's also called sharpening the vat (I suppose *technically* you can't revive a synthetic indigo vat, since it's not alive like a fermentation vat, so they needed a different word.). Essentially, indigo undergoes an oxidation reaction to go from white (soluble) to blue (insoluble / bound to fiber), and can be reduced again (back to white) by adding more of the reducing agent; you also check the pH and add some hot water to bring the temperature back up. Lesley used Thiox (thiourea dioxide) to create the vats in the first place, and fortunately I had a packet of thiourea dioxide and sodium carbonate (lime) from the Jacquard-brand synthetic indigo kit I had kicking around. So, I dissolved that in hot water, and half the indigo provided in the kit since the vat had been depleted, and added them and a bunch of boiling water to the dead vat. And, it kind of worked... it never looked like a brand new vat, but white cotton thrown into the vat came out a good dark shade. If I could have done it on a day that was 25C instead of 8C it might have worked a little better.

Flash-lit cheesecloth that was dyed solely in the sharpened vat.
I'm so happy with how this t-shirt turned out.
A heathered tissue t-shirt and the cotton twill binding tape.
Audrey in the t-shirt she dyed and white stretch-cotton jeans that got four dips in the sharpened vat.

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