This is a blog post on using iron as mordant in natural printing. Iron available most as commonly ferrous sulphate. It is a mordant as it react with tannins that occurs naturally in dye plants and flowers. As a result it produces a print when it comes in contact with moisture and heat.
Iron occurs naturally can be found as rust in old iron objects such as nails and cans. So one can obtain iron from home without having to buy iron. However, the exact quantities is not known in these items as one can’t measure it. Therefore it is much better to buy dehydrated iron powder online platforms like Amazon, ebay or crafts suppliers.
The is a eco printing technique called ‘dirty pot’ that uses only natural found mordants. It uses naturally found iron, making homemade iron water and soak the fabrics in them. Then boil in an aluminium pot with vinegar plus eucalyptus leaves and onion peels. This method only works with certain types of leaves and not flowers. Also one has got to boil the bundles for 2.5 hours. I have not tried this method due to the cost of using gas for 2.6 hours.
Using iron as mordant in natural printing
One doesn’t need much iron to natural printing about 2 grams to about 2 liters of water. I tend to add aluminium acetate mixture into iron as I don’t just want to produce dark prints. Too much of iron it will produce dark prints, too little iron no prints.
When I first started natural printing all I ever use most is iron. It works all the time. As a blanket/ carrier cloth as they call them or on its own. Blanket when soaked in iron solution is called iron blanket. It is basically a cloth commonly made from cotton that has some thickness and moisture retention properties. It produces great prints. Of course this is using correct amount moisture and heat. It is very to say what is the exact amount as so many variables can affect the outcome. So do experiment and see what works.
It only works with natural occurs fibres made of protein and cellulose like cotton, silk and wool. It will not work with synthetic fibres. But if there is mixed natural fibres it will work.