The original method of dyeing denim by which ropes of yarn are pulled through vats of indigo and then laid out on top of the roof of the factory to allow the indigo to oxidize before the next bath. It creates more consistent indigo shades than other processes.
One of the three main methods to dye indigo yarn, also see ‘Slasher Dyeing’ and ‘Rope Dyeing’.
Source: Nouvelle de Nîmes Nº 5: The Denim Dictionary
