Eco-print experiments

How long to boil eco-print bundles

When I first started eco-printing, I boiled my bundles for 3 hours. I got good results, so I kept doing this. But one day I noticed that after a short amount of boiling the leaves had already produced a lot of beautiful colour.

So I decided to take a more systematic approach to working out the optimal length of boiling. I made up a batch of small bundles using leaves from 3 different eucalyptus varieties on pieces of the same pre-mordanted cotton. I set them to boil, then removed them at 15 minute intervals.

I was suprised to see that there wasn’t much difference between the bundle that had been boiled for just 15 minutes (left), and the very last one which was left in for 1 hour and 45 minutes (right).

Comparing different boiling times for eco-print bundles

The colour of the leaves on the top sides did shift from brown to blue with longer boiling times, but the centre green and botton brown leaf prints didn’t really vary. The blue band on the right side print is from the piece of dowel that the bundles were wrapped around. This band got progressively darker and bled more the longer that each sample was boiled for, because wood has its own tannins.

Even though much of the dye has already emerged after 15 minutes, I do cook my bundles for longer, to ensure that the maximum amount of colour is transferred to the fabric and to really give it time to set. I find that about 1 hour is a good length of time when eco-printing on cotton. It’s enough time to get strong prints, while being mindful of energy use.

A comparision of cooking times for cotton eco-print bundles

Good leaves to use for eco-printing: experiment two

I get asked a lot if the method I described in my ebook will work for non-eucalypts. These samplers are a good example of the results you can get using different types of leaves. Following on from the first experiment I documented, these leaves were left to soak for about 2 months before I used them, and it really made a difference! Some of the leaves printed better than others, but I really enjoyed seeing how so many different types of leaves, some native to Australia and some introduced species, can produce such clear and beautiful prints.

I sandwiched the leaves between two different pieces of cotton, to observe the difference in the prints produced from each side of each leaf:

Green eco-printed leaves

These prints are of the ‘sky-facing side’ of the leaves (where applicable). Most produced a lot of colour, and the leaf outlines and veins are crisp and clear. They are printed onto a yellow woven cotton, which has created beautiful green hues for many of the leaves, in contrast with the bluer prints below.

Blue eco-print leaves on cotton

These prints are of the ‘earth-facing side’ of each leaf, on a white stretch cotton. Some still printed very clearly, especially the maple, oak and blackberry leaves, while others produced only faint outlines.


Mordanting with blood

I’ve been curious about mordanting with blood ever since I read India Flint’s passing reference to it in Second Skin. I’m not a squeamish person and I have ready access to a cruelty-free form of blood each month with my menstrual cycle, so I thought I would give it a go. I wondered if it would give similar results to other protein mordants, or whether the particular properties of blood would effect the results.

Mordanting fabric with blood

To prepare the fabric, I simply soaked it for about an hour in the water I had soaked my cloth pads in. Then I lay it flat to dry and let it set for about a week before eco-printing.

Eco-print with eucalyptus leaves on fabric mordanted with blood

The mordant definitely worked, although the prints were fairly light. Next time I would try to use more blood and soak the fabric for longer to create a stronger mordant. I might also try a series of ‘dipping and drying’ as is done with soy mordants, and see if this gives more vibrant results.

Eucalyptus eco-print on blood mordanted fabric

Eco-printing on wool versus cotton

I prefer eco-printing on cotton rather than wool for a few reasons. Cotton clothing is easier to find at op-shops, and in a wider range of styles, than wool. Upcycling clothing that already exists feels like the most ethical way I can do a lot of eco-printing, so it makes sense to go with what is readily available. I also love the wider range of colours and textures that I can get on cotton. Eucalyptus leaves mostly print solid colours on wool, whereas prints on cotton often have extra details like blue dots.

Eco-printing on wool versus cotton
When I was writing my ebook, I wanted to show the difference between wool and cotton eco-prints. I did a range of small samples with the same leaf sandwiched between one piece of wool and one piece of cotton. It was so interesting to see the different colours that came from the exact same leaf on the different types of fabric. All of these photos show the wool on the left and the cotton on the right.

Eco-printing on mordanted wool

Some of the mordant on the cotton did transfer somewhat onto the wool, seen most starkly in the dark borders around the leaves and gumnuts above, so I can’t expect the same results with these leaves on unmordanted wool.

Eco-printed wool and cotton colour comparisons

I was especially excited to get some more insight into which leaves dye best on wool. Lots of the eucalyptus leaves here in the Blue Mountains dye quite pale, especially without any mordant. I noticed that I got beautiful bright oranges from silvery-blue leaves, while the greener leaves dyed pale yellows on the wool. Almost all of my local gumtrees have dark green leaves, so I guess it’s lucky I’m not often wanting to get bright prints on wool!

Bright orange and brown gum leaf eco-prints, from the same leaves on different fabric

Even more interesting, the leaves that dyed orange on wool consistently dyed brown on (iron-mordanted) cotton, while the leaves that dyed pale yellow on wool dyed blue or blue-green on cotton. I know that some green eucalyptus leaves do dye brilliant reds or oranges, but my local ones don’t seem to have the right chemical components for that.

Gum leaf and gumnut eco print experiments

I still have a lot that I want to investigate about different types of gumleaves and what factors influence which colour they dye, but this was certainly a useful experiment and a very good way to get to know more about my local leaves.

Comparisons of eucalyptus leaves eco-printed on wool versus cotton