Posted by Mallory Gehrer
When entering an art exhibit, we as viewers never quite know what we might find. Each piece tells a story, and Rowland Rickett’s “Ai no Keshiki — Indigo Views” dramatic piece tells a story through a color everyone can recognize -- indigo. The Washington Post highlighted this piece earlier this year in May, calling it both “gossamer and imposing” in preparation for the exhibit to open once more. I was struck by this piece as it truly felt like a force of nature, which is what the exhibit it is housed in is called. While indigo is commonly synthesized today, it was once a natural pigment that was extracted by hand. It is the commonplace blue dye of today, most recognizable in blue jeans. When making each fabric square, the artist grew and extracted his own indigo dye and gave each fabric square to a person to use and return to him. It is in this sense that the indigo becomes more familiar to us, like a pair of well worn jeans, and each piece tells the story of the person who once owned it. But to the more curious, they might wonder how this artist extracts and uses his own natural indigo dye.
Historically, indigo dye was extracted from any Indigofera species. The leaves are soaked in water in order to hydrolyze indican into indoxyl, which oxidizes to indigotin (indigo dye). A strong base added to the solution causes indigotin to precipitate out, and the powder can be dried, pressed, and used as a pigment.
But the process does not end there. To use it for dyeing fabric, indigotin must be reduced first in a reducing solution because indigotin is insoluble in water and alcohol, which makes it practically impossible for fabric to be dipped into a dye bath. This reduced form is called leuco indigo and it has a greenish-white color.
The fabric can then be dipped into the leuco indigo solution, and when it is removed, the leuco indigo oxidizes once more in the air back into indigo blue, creating the all-too familiar blue color we see in today's jeans and other clothes. The variety of blue shades depends on how many times the fabric has been dipped in the dye bath.
Indigo is a unique dye in the sense that it doesn’t need a mordant, which is usually an acid or a salt, in order to bind with the fabric. Common mordants are alum, tannic acid, or sodium chloride, and they chemically bind dyes with fabric through forming coordination complexes with the fabric. Indigo instead directly oxidizes and binds to the fabric, which also allows it to be dipped multiple times to increase the amount of dye on the fabric as shown above.
Perhaps it is this unique combination of traits that made Rowland Rickett decide to grow, harvest, and dye indigo for his exhibit. Not only does indigo bring people together through our jeans and clothes, but it also literally binds closely with the fabric it is affixed to. Each harvest, each dye bath, and each dip of the fabric creates a unique shade of indigo, much like the people he gave the dyed fabric to. It’s this reflection of life, time, and bonding through human interaction and chemistry that allows this exhibit to tell a story that truly is a force of nature.
References
Jenkins, M. (2021, May 11). At the Renwick Gallery, four ARTISTS conjure Mother nature out of FABRIC, metal, glass and paper. The Washington Post. Retrieved September 12, 2021, from https://www.washingtonpost.com/goingoutguide/museums/renwick-gallery-forces -of-nature-art-review/2021/05/10/5e88d48c-ae7b-11eb-b476-c3b287e52a01_stor y.html.
Chanayath, N., Lhieochaiphant, S., & Phutrakul, S. (1970, January 1). Pigment extraction techniques from the leaves OF Indigofera tinctoria Linn. AND Baphicacanthus cusia Brem. and chemical structure analysis of their major components: Semantic Scholar. Semantic Scholar. Retrieved September 12, 2021, from https://www.semanticscholar.org/paper/Pigment-extraction-techniques-from-the-l eaves-of-of-Chanayath-Lhieochaiphant/06b452aa6340684d1663c9ef42811621fe c71a33.
Keegan, G. (n.d.). Indigo vat basics. NATURAL DYE RESOURCES, PLANTS, KITS AND WORKSHOPS. Retrieved September 12, 2021, from https://www.grahamkeegan.com/indigo-vat-basics.
Indigofera. FineGardening. (2018, January 24). Retrieved September 12, 2021, from https://www.finegardening.com/genus/indigofera.
Good title. Your introduction works pretty well at drawing us in. I like the personal note that the piece struck you as a "force of nature." Your explanation of growing and processing the dye is very good. Your explanation that the dye doesn't need a mordant is good and helps us understand the significance of the art. It would be interesting to know how it binds to the fabric. Your graphics are quite well chosen. The chemistry equations will be more informative to some than to others, but everyone gets a sense of the complexity of the process. There seems to be an superfluous double bond between the carbonyl carbon and the adjacent aromatic carbon in the indigo blue structure. I assume that was in the article. Interesting. Overall a good post.
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