Indigo - crafts
Indigo as a blue dye
Indigo is around you every day, because denim jeans are dyed with synthetic indigo. Jeans have an incredible history. Having started out as tough working clothes they have become incredibly popular across all age groups and around the world. Denim gets its characteristic appearance because normally only the weft threads in the fabric are dyed and often the dye tends to rub off.
|Image: Dyeing and printing indigo cloth|
Dyeing methodsTo make a patterned fabric the indigo can be prevented from dyeing some areas by painting wax onto the fabric in a pattern to resist the dye. After dyeing with indigo, the wax is removed by boiling. For some fabrics the un-dyed areas are left white, but for traditional blue-white-red fabrics the cloth is then given to another dyer who specialises in red dye.
Another method of creating patterns using indigo dye is to dye fabric all over with indigo first and then remove dye from some areas by printing with bleach. This is called discharge dyeing and was not used much until the 19th century. Its use was revived by William Morris. Indigo cannot be used for block printing, where the dye is painted onto patterned blocks and pressed onto the fabric. This is because to work properly the dye needs to oxidise from indigo white to indigo blue on the fabric, not on the blocks which are exposed to the air.