Maple leaves are high in tannins and so are well-suited to the eco-print process. Tannins help natural dyes bond to fabric and often also impart colour. Tannin levels increase over the growing season. So maple leaves picked in autumn will print more vividly than those picked in spring.
The different sides of maple leaves produce quite different effects. I like the delicate details of the sky-facing side of the leaves:
But the earth-facing side will produce darker prints and be more colourfast:
Before eco-printing, I soaked the maple leaves for a month to get rid of excess tannins, which bleed when combined with the iron mordant. The soaking process helps produce clear, crisp prints. Find out more about which leaves can be used for eco-printing on cotton and how to prepare them with my ebook, The Leaf Guide.
Although iron is my trusty favourite mordant- easy to make, relatively low toxicity, and easy to dispose of- I have been experimenting with alum lately. My first results of eucalyptus on alum were not very promising. Fluro yellow is not my favourite colour. But then I tried double-mordanting, combining both iron and alum. I hoped that the saddening effect of iron would help tone down the brightness of the alum and bring in more subtleties. And it worked beautifully!
The alum has brought out these beautiful oranges and yellows from the eucalyptus leaves, while the iron gave more depth and detail:
The colours vary according to how much alum and iron are used, and the particularities of each piece of cotton too. It is important when eco-printing to be open to the different possibilities and to embrace the results you get. Each print is a gift from the leaves, so be grateful.
This onesie was bit of a failure originally. It had pale, faded grey prints, probably from not being scoured properly. The alum and iron mordanting prepared it well for a second round of eco-printing, and it was transformed into one of my favourite pieces so far. Aren’t the gumnuts exquisite?!
To do this double mordanting, I scoured the cotton, gave it a short dunk in one mordant, let it dry and cure, then dunked it in the other. Then I eco-printed the fabric in my usual way, using the instructions I share in my ebook Gum Leaf Alchemy.
Combining alum and iron mordants to eco-print on cotton
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:
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.
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.
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.
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.
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.
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!
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.
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.
