Iron can be used as a modifier to ‘sadden’ the colours making them darker and more sombre in tone; reds become more purple, whilst yellows and oranges turn greener. (Iron does not modify the colour of woad or indigo and it does not seem to modify the colour of chlorophyllin extract either.)
handspun wool dyed with coreopsis extract below & dyed with coreopsis extract & iron above
1. Measure the Iron A small pinch of iron salt (ferrous sulphate) is usually enough to noticeably modify the colours. You might find it easier to measure a pinch using the back of a teaspoon handle (reserved just for dyeing) rather than using finger and thumb covered by rubber gloves. Buy iron (ferrous sulphate) here.
2. Dissolve the Iron Dissolve the pinch of iron salt in a container with warm water before adding it to the saucepan.
3. Add to the dye pot To get an even colour, it is best to remove the fibres from the saucepan, add the dissolved iron salt, stir it well and then add the fibres back. If you do not get the colour you want, add another pinch.
Alternatively you could add the dissolved iron modifier to another saucepan 2/3 full of warm water, stir it well and then add your fibres.
4. Remove from pot Do not leave the fibres more than a couple of hours in the pot with iron and wash fibres well after using an iron modifier.
