Textile of the Week: Cold-Water, Fresh-Leaf Indigo Vat Dyeing  冷水生葉藍染め
 Three samples of fresh-leaf, tadeai vat indigo: fresh leaves with silk (left); fresh leaves on ramie with a little calx (calcium hydroxide) added to the vat (center); and fresh leaves and calx on cotton (right).
So, what about the cellulose fibers? Not to worry. We need only take the pH of the fresh-leaf vat from neutral to around 10.5 by adding dissolved calcium hydroxide (chalk) to a fresh vat and allowing the mixture to simply sit for about an hour. Repeat the steps you followed for the silk. You should wind up with a very beautiful blue –not quite as lively as the fresh-leaf dye on silk, but still a very refreshing turquoise.
 Textile of the Week cards – scroll down to the bottom of this page for more details.
I’m presenting the following four samples in a cluster of four to show off the range of colors available with the noncomposted, raw, fresh-leaf tadeai dye.
Let’s take a look at using fresh-leaf indigo in vat form. I’d like to begin with the various shades of robin’s-egg blue, now that you have had a chance to try your hand at direct contact with indigo leaves in Fresh-Leaf Indigo, It’s Magic!
Fresh-leaf vat after just one dip, silk damask (donsu).
Eggs of the mapuche chicken – Who wouldn’t love these colors?
We’ll take a beginner’s look at the most basic form of indigo vat – one made simply from fresh leaves and cold water. I’ll be using the Japanese tadeai indigo, but other varieties will work well, too.
Just after sunrise, on a cool mid-summer morning, use a scythe to gather a basket full of fresh leaves. Choose plants that look healthy and are deepest in color, preferably ones that aren’t yet in bloom.
Fresh-leaf vat after two long dips, crinkle-weave silk.
The fabric above,right, is silk, as are the other samples on this page. This particular weave is called chijimi, the weave structure will be covered in a future issue. It scrunches when wet and must be stretched out again before using it to sew.  But the scrunching brought out an interesting trait of the fresh-leaf indigo when used as a simple cold vat.
Add the leaves to a blender with ice water and churn until the leaves are thoroughly pulverized. Strain. The resulting liquid is your vat and you are ready to go! This particular vat works best with protein-based fibers, so primarily silks and wools.
I imagine you were paying attention when I mentioned above that you must keep turning the fabric in the cold vat to prevent streaking. If you simply dump the material into the vat and come back later, the areas exposed to the larger volume of liquid will have a greater pool of colorant to pull from, even though the dye is uniformly dissolved in the water initially. Think of the person who walks into a room and seems to suck all of the oxygen out of it. That kind of person lessens the odds that there will be enough oxygen to go around – and your odds are decreased the closer you stand to the offender. The fiber is doing just that – sucking all of the color out of the liquid in close proximity. So bunched areas will quickly deplete what pigment is available to them. The surfaces on the perimeters are able to pull from passing currents and realize a deeper, more fulfilled experience.
   Or just cram it in the pot and be done with it. Streaks can work.
The weave structure forced the fabric to scrunch up tight once wet.
Straining the pulverized tadeai leaves through a polyester rag, cookie brittle is optional.
Wash your material thoroughly and rinse in cold water. The longer you soak the material, the richer the robin’s-egg blue. Whether you are using yarns or woven yardage you will want to keep the fiber moving for the most evenly colored results. You may simply swish the material periodically, or you may suspend it from rods and continuously turn it. Whether it is a books-on-tape thriller, or simply the neighbors going at it again next door, make sure you have something prepared to occupy your mind since this will take up to an hour or more for the color to develop.
Uneven absorption of the indigo caused by the scrunching of the yardage when wet. This sample has been ironed out flat to exploit its visually eccentric nature.
The above two samples are the same piece of fabric. The one on top is shown as it appeared after being taken from the vat and allowed to dry. It was when it was ironed out flat that the streaks became appearant, as you see in the sample on the bottom.The peaks (the exposed areas of the scrunched yardage) have absorbed the greatest amount of color – the valleys had less direct access to the dye in the vat.
The same yardage as shown above, draped. The folds show off the iridescent quality the varying shades of indigo impart. Notice the little sticky-out bits of yarn, making it look a bit like a case of shingles? This is actually a very sought after and expensive look. It is called hige-tsumugi, or bearded slub weave.
 The yardage has been sewn together at the ends to create a loop. Using a set of dowels to help hold a portion of the fabric above the vat, John is picking up and pulling the fabric toward himself as the silk cycles through the dye below.
Remove the yarn or yardage from the vat, wring, rinse, dry, and you’re done. Since this vat is pH neutral, there is no need to subject the dyed fiber to a vinegar rinse. In contrast, many Japanese like to give it a dip in a slightly alkaline solution (1 teaspoon of calcium hydroxide dissolved 3 gallons of tepid water). However, this does have the potential to take the color just a bit to the indigo-grey side.
 The same yardage as above, draped.
The samples, left and below, have been dyed using the same yardage from the same bolt of Japanese silk jacquard (rinzu) to help you gain a better appreciation of the range of shades available.
   Both have been dipped into the same fresh-leaf indigo vat outlined above. They appear grayer than the first two samples because a little calx (calcium hydroxide) was added to the vat to bring up the pH a bit. The sample to the left was dipped once, and the sample below twice.
Clamp resist on silk leno in fresh-leaf indigo vat.
This method works wonderfully with resist techniques that can hold up to prolonged exposure to cold water, such as kasuri (ikat), rozome(batik), and clamp-resist methods.
Cold-vat, fresh-leaf indigo vat with calx, one dip, Japanese silk jacquard (rinzu).
copyright John Marshall, 2015
Cold-vat, fresh-leaf indigo with calx, two dips, Japanese silk jacquard (rinzu).
John harvesting tadeai just after sun up.