lightly re-dyeing with indigo
A traditional dyeing technique where fabric is dipped again in indigo to refresh or deepen the color. Domain-specific term used in textile and craft contexts.
When you do a light indigo re-dye, the color becomes deeper and more vivid.
Compound of 藍 (indigo) and 返し (returning/doing again), literally 'indigo returning'. The exact historical derivation is uncertain, but the term reflects the process of dipping fabric back into the indigo vat.