Indigo Gives America the Blues, Timeline


Illuminated Discharge: Mid- to Late-1800s

Illuminated Discharge: Mid- to Late-1800s

Technological breakthrough:
Adding a coloring agent to the bleaching agent, resulting in a one-step printing process

What to look for:
Small yellow or orange designs on a blue background; good registration

Illuminated discharge printing produces colored patterns—often in yellow or orange, rather than, or in addition to, white—on a pre-dyed background. The discharge paste contains a coloring agent that chemically reacts with a substance in the clearing bath that follows the discharge process. Because the discharge paste and coloring agent are applied in a single step, the colored design has good registration, or design matching.