Slate Black Mud-dyed Hand-sewing Thread 1100 meters

30/2 cotton thread slate black hand-dyed brown with mud and tannin (1100 meters / 1200 yards) This thread has been hand-dyed at our studio in Ubud, Bali, with an ancient technique used across Indonesia. We use rice field mud that we ferment with starch water from washing rice and boiled extract of Woodfordia floribunda flowers as the tannin source. Muds used for mud dyeing are typically pink down to about 20 cm and then black below this. The pink colour is hydrated ferric oxide or rust (Fe2O3), which is insoluble and red coloured. Below 20 cm the mud is oxygen-depleted and iron reducing bacteria live by reducing the rust to release the oxygen that they breathe. This produces ferrous oxide (FeO) which is soluble and black, and sought after by mud dyers. When ferrous oxide reacts with tannin it makes the black dye iron tannate. Traditional dyers therefore pre-dye with a tannin before soaking in mud to colour their textiles black.