Indigo Gives America the Blues, Timeline


Discharge Printing: Mid- to Late-1800s

Discharge Printing: Mid- to Late-1800s

Technological breakthrough:
Developing a discharge (bleaching) paste that would work on indigo

What to look for:
Small, repeating white designs.
Caution: it can be difficult to differentiate between discharge prints and resist prints

Discharge printing creates white patterns on a colored background by applying a bleach (discharge paste) to pre-dyed fabric. In 1826, an English textile printer, James Thomson, developed one of the first successful discharge methods for indigo, which used oxalic acid, because chlorine bleach would not remove indigo as it did other dyes. Thomson’s discharge paste was printed onto pre-dyed indigo fabric, then the cloth was boiled in a chalk bath to achieve white patterns on a blue ground.