Eco printing with leaves

 This workshop involved getting to grips with a technical process that produced remarkable results.

It was led by Caroline Nixon, who was an excellent teacher giving very clear instructions. Even so, the process requires a lot of equipment, careful preparation, uses expensive fabric and provides variable results. I have never done eco printing before so I think I got good results as a beginner. The above piece was my very first go where I was just testing out which leaves printed well.

The basic process of eco printing is to use a combination of natural fabric soaked in mordant, leaves high in tannins, pressure and heat from steam to print without any other dyes. I completed this workshop in February but collected many of the leaves back in November, preserving them either by drying in a flower press or freezing in sandwich bags.

The leaves I found to be successful were oak, alder, cercis, liquidamber, maple/acer, chestnut, cotinus, eucalyptus, rose, raspberry, blackberry, blueberry, ornamental blackcurrant, perennial geranium, and ferns. Other members of Textileartist.org Stitch Club also had success with sage, alder catkins and bladderwrack seaweed.

The fabrics I used were all pure silk - most pieces are Silk Noil, which is a slightly slubby absorbent silk that I had never used before but I also tried silk dupion, habotai and organza - you can get a handy silk sample pack from www.thesilkroute.co.uk. You can also use wool, linen or viscose. I didn't have any of these fabrics just waiting to be used in my stash so I bought just half a metre of silk noil and the silk sample pack to try out this process.

First you have to prepare your fabric by scouring it to remove any dressings in the fabric from manufacture or any previous washing powder residues. With silk this just involved putting it in the washing machine with non-bio delicates washing liquid on the silk/wool setting. You need to use damp fabric for the eco printing process so I kept my scoured pieces in a zip-lock freezer bag once out of the machine. For the other fabrics you also have to scour them with soda ash either in the machine or boiled up on the stove.

There is an extensive equipment list for eco printing, which was quite off-putting to gather together:

• Large wide pan with lid - needs to be no longer used for food preparation 
• Something to act as a steamer rack in the pan - I used chicken wire but rocks, and silver foil were also suggested
• Round poles to fit in the pan  eg metal pipe or wooden pole
• Plastic sheet to protect working surface
• Clingfilm or foil
• Binding strips eg string, bandage, T-shirt yarn or pantyhose
• Washing up bowls
• Old towel
• Plastic gloves
• Scissors
• Tongs
• Measuring spoon

First I had to make up the mordant. This is the chemical that helps bind the plant pigment to the fibres in the fabric to make the printing permanent. We were shown how to use iron. You can buy ferrous sulphate powder easily online or you can chuck some iron nail or bolts into a jam jar of water with a splash of vinegar and make your own rusty water. I decided to buy the powder as it would be one variable that I could control more easily. You need to make up 0.25ml (1/4 teaspoon) of iron powder to 4 litres of warm tap water. I also had another washing up bowl of water to soak my dried leaves in to make them pliable again.

Wearing gloves I took my damp fabric, soaked it in the iron water for a few minutes - it went noticeably rusty coloured. The I wrung it out very hard over the bowl - it mustn't be too wet. You can use an old towel to help for larger pieces of fabric. The I laid the fabric down on a rolled out piece of cling film and started arranging the leaves. We had been told that for some leaves the back prints better than the front due to the pores on the underside of the leaf. As I had short poles to fit into my pan all my pieces of fabric were folded so you can see in the piece above that there is quite a difference on the front and back for quite a few leaves.

Then I rolled the fabric and cling film together very firmly around my pole to ensure close contact between the fabric and the leaves. You can see that I covered my underlying pole with foil to ensure that any natural colour in the wood did not transfer in the process.

At the end of the fabric I went once round again with the cling film to seal the whole bundle so that the steam can't get in. Finally I bound it tightly with the strips of pantyhose.

Then they were ready for the pot! 90 minutes steaming is required so you need to keep checking up that it hasn't boiled dry.

You can see that I was forced to use a camping burner in the garage, which at least meant that the kitchen wasn't full of steam and the smell of hot leaves! At the end you need to take the bundles out with tongs and leave to cool before unwrapping and removing the spent leaves.

The unwrapping is pretty exciting! In the piece above on silk dupion I put circles of red and brown onion skin between the leaves to see what happened. You then have to leave the fabric to 24 hours to ensure the pigments fully combine with the fabric before washing in the machine with non-bio delicates liquid on the wool/silk wash again.

Cercis and oak on silk habotai

Cercis and oak on silk organza

Various leaves on silk Noil

The I found out that you could use the same process on paper - any kind of paper that will stand being soaked. I used lining paper and got really good results. I loosely folded the paper and left it to soak in the iron water. Then held it over the bowl for to drain off until it didn't drip any more. The rest of the process was just the same.

Leaves laid on damp paper

Bundle just unrolled with spent leaves

Dried result

Alder leaf on paper

Obviously you can't wash the iron out of the paper but it was quite wrinkled from the binding so I soaked some small pieces in water for a few minutes and ironed flat underneath a tea towel. I have started making these into lovely cards.

Finally I tried a different version which we were told only works with certain kinds of eucalyptus on wool or silk and uses white vinegar instead of iron. I had noticed that there was a very tall eucalyptus tree on the edge of our local park - it had no lower branches that you could take leaves from but over winter a branch came down in a storm and on my daily walks I have been bringing bits of it home! It is basically dead by now and very brittle so I gave it a soak overnight in water to try and soften it a bit. The silk was left to soak for 30 minutes in warm water with a good splash of white vinegar. Other than that the process was the same, except the steaming is for 3 hours!

You can see I tried to keep small stems together with the seed heads and I was astounded by how beautiful this was. I was lucky that this was the right type of eucalyptus to print orange using this process.