Metal salts can be used to add to a dye bath or used as a separate bath or as an overdye. The latter is especially useful to gain a pattern on cloth where an initial layer of dye is patchy. You can tie or peg parts of dried cloth or an item of clothing and place in a bucket filled with a solution of iron and water at a ratio of 1g of iron to 500ml of water.
Iron can cause damage to animal fibres, so this should be avoided and only used with plant based materials
For 100g of cloth fill a 10L bucket or pan with warm water till ¾ full. In a measuring jug dissolve 15g of ferrous sulphate( iron) with about 100ml of boiling water and add to bucket. Stir and add cloth, clothing and leave for 30 minutes. Remove from items from bucket, wring and leave to dry. Rinse in cool water.
It is easy to make your own iron water by collecting old nails or any other pieces of metal that appears to be rusting and place in jar with 1/3 white vinegar and 2/3 water. You can then use this liquid as your modifier, although experimentation will be required as it is difficult to know the strength of the iron applied.
Notes prepared by Katrina Barnish for Sewing Café Lancaster sewingcafelancaster@gmail.com