My eco printing so far has been a bit hit and miss, so I thought it was time to be a bit more systematic. From the reading I’ve done on the subject, there are so many variables – from the pH of your water to the time of year you pick the leaves or flowers – but I thought it would at least be useful to have a few reference samples to work from.
I used four different types of fabric:
- white merino felt
- white cotton (pre-mordanted with aluminium acetate)
- lightweight cream silk from an old wedding sari
- some sort of synthetic open-weave fabric from an old curtain.
Only the cotton was pre-mordanted – the other fabrics weren’t treated in any way.
Then I prepared four different mordants:
- alum solution
- iron solution (well, not really! I’d bought some ferrous sulphate but couldn’t find it anywhere, so I ended up shaking some rust flakes in water in the hope that the effect would be similar. Of course, rust doesn’t dissolve in water, so this was pretty pointless really).
And the vegetable matter I was testing:
- eucalyptus leaves
- rose leaves
- oak leaves
- Japanese knotweed leaves
- onion skins.
I laid out a strip of felt and put five eucalyptus leaves on it. The first one had no mordant; the other four were each dipped in a different mordant. I then laid five rose leaves next to them, treated in the same way. I put the strip of synthetic fabric on top, and rolled the bundle around a piece of bamboo, and tied it up. This was bundle 1.
I repeated this three more times with different combinations:
- Bundle 2: cotton and silk with eucalyptus and rose leaves
- Bundle 3: felt and silk with oak leaves, Japanese knotweed and onion skins
- Bundle 4: cotton and synthetic with oak leaves, Japanese knotweed and onion skins.
I colour coded them with different bits of yarn, although it was pretty obvious which was which. Then I steamed all the bundles for 1.5 hours and left them to cool overnight.
The results were mixed, to say the least.
The onion skins were by far the strongest on all fabrics except the felt, whichever mordant was used.
The cotton gave the strongest prints overall, in rather an acid yellow (presumably due to the aluminium acetate mordant).
I was most disappointed with the felt – the best prints were the eucalyptus and the Japanese knotweed, but they were very faint.
Very little printed on the synthetic fabric at all, as far as I could see.
Why were these prints so faint? I’ve seen amazing prints produced by textile artists like Irit Dulman, especially on felt. I wondered whether steam alone can penetrate right into the bundle of felt, which is fairly thick. So I did another experiment where I submerged the bundles in a pot of onion skin dye – this will be the subject of a future post! 🙂
In the meantime, to try to darken the prints, I put all the samples above into a post-mordant of ferrous sulphate.
The iron worked wonders on the silk. It really brought out the Japanese knotweed prints, turning them a dark khaki. And the eucalyptus and rose leaves became much more distinct.
The prints on the cotton that were previously strong yellow turned much darker, and two of the oak leaf prints that were previously very faint came to the fore beautifully.
Even on the synthetic fabric the prints were now faintly visible, whereas before they were practically non-existent.
The felt remained disappointing, however.
So maybe if I’d used a proper ferrous sulphate mordant on the leaves before steaming, the results would have been different – who knows?