Iron used as a mordant improves light- and wash-fastness of most dyes, and particularly logwood. According to Liles, iron mordant produces quite beautiful results with cochineal; iron and madder make Egyptian purple, violet and brown; whilst iron, tannin and madder are used in India for greys, blacks and purples.
It is best to use iron mordant only on cellulose fibres like cotton and linen as too much iron can damage wool. Buy iron (ferrous sulphate) here.
You will need:
- 2 to 5 grams of iron salts
- 100 grams of cotton fabric
- 8 to 10 litres of water
Scour your fibre well beforehand and leave it to soak in water for at least an hour or even overnight. Fill a saucepan ¾ full of warm water. Pour boiling water in a small heatproof container and add the iron salt, stirring it well until it has dissolved. Then add the dissolved iron mordant to the saucepan with the dye and stir well.
Add the pre-soaked scoured cotton to the saucepan. Raise the temperature of the saucepan to a simmer and simmer gently for an hour. Make sure the fibres are submerged, and keep turning the cotton to avoid streaking and spotting. Leave the cotton to cool in the saucepan. It is important to rinse very well to remove all unattached iron particles.
a) What is the Iron sold for dyeing? (opens a new page)
b) Iron as a Dye Modifier (opens a new page)
c) Iron as a Mordant (this page)
d) Dyeing with Iron (opens a new page)
e) History of Dyeing with Iron (opens a new page)
f) African Mud Cloth (opens a new page)
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