How to Indigo Dip and Tending Your Vat
Proper and comfortable dipping technique is crucial when you are dyeing in indigo. The idea is to get the most complete pattern, even coloring, all while keeping your indigo vat properly balanced and reduced.
Shibori Resist techniques have been in use for 1300 years and break down into a few broader categories:
- Hand knotting with tool
- Folding and Clamping
- Machine Aiding (starting 1970s)
“In shibori there is a right and traditional way but there rarely exists a wrong way.”
Comes from the Japanese word Shiboru: to tie, squeeze or wring out. However where ever there is dyeing in the world, there is some sort of traditional resist techniques.
Fabric Prep and Dyeing
- Stitch, fold, tie, and/or bind fabrics.
- Soak completely in water (a few minutes at least, but the more the better especially for thick fabrics)
- Squeeze out any excess water/air from fabric, set aside.
- After “flower” is removed, or surface cleared, slowly submerge fabric and manipulate under the dye surface, being careful not to drop as there is residue at the bottom, or overwork/agitate the solution. Less oxygen exposure the better.
- To remove, squeeze fabric beneath the surface and slowly remove to avoid agitating the solution with dripping. You should have a collection tray to gather the falling indigo to save but also save your vat from the splashes. Ring out as much indigo from your piece as possible in this tray, as you can reuse it!
- Set aside each piece to expose to oxygen in the air, 20 mins max. Until it turns blue is good enough. It will depend on the fiber and the style of binding, how long exactly this will be necessary. No green should be left. It may also be helpful to rinse your pieces in cold water between dips. Especially when dyeing in a ferrous vat, or dyeing an "all over" blue rather than a pattern.
- Repeat, to desired level of blue. It will be two shades darker than you expect because it is wet and you will wash some out. If you like the blue that it is, dip two more times.
Washing After dye treatment is critical. You don't want bleeding, discoloring, and fading
-Rinse in cold water to remove a good amount of indigo before you unbind/unbundle. You can give a quick rinse after too put don't agitate too much.
-Fabric should then be soaked in an acid bath for 15-30 minutes or overnight, to deactivate the reducing agent and it also helps set or “fix” the indigo. (White vinegar 1 cup per gallon bucket, people will say "a couple of glugs per gallon" as well. Citric Acid is about 1 cup per 5 gallons.) If you don't you'll get yellowing and fading.
-Soak in hot hot (130degrees) water for at least one hour or until water is cool. You need to loosen dye particles that haven't adhered.
-Wash in hot water and mild detergent like dove or dr. bronners, but synthrapol highly recommended. It helps with dye bleeding by suspending dye particles.
-Final wash in cold water.
During the life of your piece, continue to wash your piece in cold water and avoid intense, direct sunlight.
Tending the Vat Vats can kept for years if used frequently, cared for, and stored properly. Prereduced vats keep a month maximum, natural vats one year to many. You shouldn’t store a natural vat for more than 6 months unused. You'll smell if it's bad.
Stored vats can be brought back up to temperature if necessary for reducing agent used and then pH tested and adjusted with reducing agent and alkaline.
Disposal of Vat Keep your vat as long as you can, but when ready you should neutralize the lime/hydro before pouring down the drain. Adding vinegar will do the trick but also whisking vat to add air, turning the lime into calcium carbonate aka chalk/limestone, will make it safe enough to compost. (natural vat only)