When yarn or fabric is first pulled from a natural indigo vat, the leuco-indigo compound is a pale, yellowish-green. Ungreening is the mandatory oxidation process where the textile is hung in the air, allowing the dye to react with oxygen and precipitate into the final, insoluble blue pigment. The material must be fully ungreened before being dipped again to build darker shades.
Heard on the job
Hang those skeins on the rack to ungreen for at least twenty minutes before you give them a second dip in the vat.
Also heard as
- oxidize