That's pretty cool

However, the documentary “Shades of Indigo” follows self-taught indigo dyer Ryuta Sasaki, who practices a traditional dyeing technique that involves mixing crushed indigo leaves with wood ash and water to kickstart the fermentation process. Over time, the indigo dye becomes a living entity (similar to a sourdough starter), with its color changing slightly from day to day. Experienced dyers can even sense the “mood” of the dye by its smell and taste. One of the most moving scenes in the documentary shows Sasaki expressing gratitude and saying goodbye to an old indigo vat he had affectionately named “Great-Grandma” after she stopped producing color—a reflection of the deep bond he had formed with it.