Eco Printing on Cotton

Combine my stubborn streak with this mysterious art form of ‘Eco Printing’ and you have a whole lot of unique prints! I have been completely obsessed with this way of printing especially on cotton. Eco printing uses natures gifts in the form of leaves (and sometimes flowers) to create a transfer print to fabric without the use of ink or painting (so no drawing or painting skills needed). Come see this magic of Eco Printing on Cotton…

Preparing the Cotton Fabric:

As I had mentioned in my earlier post, each type of fibre needs to be readied for taking the colour from the leaves. To make sure you are starting with the cleanest possible fibres you should scour your fabric. Most fabrics have some coatings, starches and buildup of oils. Scouring is a strong cleaning to get of these impurities. Cotton should be scoured with a 2 hour simmer in a washing soda (soda ash) solution. Rinse out all the ‘dirty’ water once cooled enough to handle.

Cotton is fairly inexpensive so it seems a great fibre to start with. That is what I thought; however it turns out it is more difficult to print on cotton and other cellulose fibres (such as linen, rayon, hemp) than it is on protein fibers (such as wool & silk). With that said, preparing/scouring and pre-mordanting cotton is even more important.

The pre-mordant that can be used with cotton is soya milk. Multiple ‘soak and dry’ cycles help the fibre allow printing. Aluminum acetate (make at home using alum, washing soda & vinegar) is another possible pre-mordant however soya milk is readily available.

One of the printing mordants that I like to use is iron. I make a bucket full of rusty items and water to create a solution of iron. Vinegar can help you along to create an iron acetate. You may also buy iron sulphate and then use specific recipes for your iron solution. But the artist in me likes to be a bit more adventurous and leave some to chance, but it takes patience.

Oh the Mystery:

As a side note; this Eco dyeing art form is very satisfying when it all works, but it will not always happen. If you want perfect results each time, then find another print method. ‘Just as in life; things that are more difficult to get are usually worth more…’ That’s my theory and I accept the ‘duds’ as part of the process.

I have spent months learning and reading and testing and testing some more. But just like a degree in chemistry it is still no where near knowing it all. But that is also the beauty of this Eco printing; it keeps you yearning to learn more and trying new variations to make beautiful textiles.

I am a great observer. I had left a leaf in the iron water for a couple days and when I noticed it there was some great blue-black created by the iron and the tannins in the leaves. Ah-ha! A chemical reaction of sorts; so much fun!

Materials Needed:

  • Cotton Fabric (practice on ripped strips of cotton bed sheets)
  • strong string of some type (butchers twine is great)
  • scissors
  • some round type of dowel/pipe to wrap the fabric around (thicker is a bit better) (old wood curtain rods work well, copper pipe, piece of pvc pipe )
  • tray to soak leaves in
  • rags/towels (to soak up extra messes)
  • gloves
  • extra old sheeting (optional to make ‘Iron Blanket’)

Step #1 Prepare your leaves

Depending on the time of year, you may have fresh or dried/pressed leaves to dampen. I let them soak in the iron water for at least 30 minutes (enough time to get set up)

A long table is great, and placing some plastic or tarp to protect against stains (from iron)

In reference to the leaves, there are some that are more sure to print well. Maple leaves, japanese maple, rose, sumac, eucalyptus, smoke bush, black walnut, red maple leaves etc. have high tannin content. You will find your favourites. The weather, time of year, area, all play into the way that the leaf prints. The underside tends to print stronger as well.

Is your head spinning yet? That is why you need to take notes, for future reference.

Step #2 Place the leaves

These sheets were scoured in washing soda (not baking soda) well and no other treatment. (see further down for more pre-mordanted cotton methods)

The dipped leaves are placed so that there is a good coverage. Some are facing up and some down.

Step #3 Roll’em Up

Roll it up tightly to keep the iron-dipped leaves well flattened to the fabric. At this time I was not aware that there may be bleed through to other layers (like a fabric sandwich). A layer of ‘barrier’ plastic drop cloth can be put on top of the leaves to make sure there is no bleed through.

Step #4 Tie the Bundle

To keep the fabric tight to the leaves, wrap at regular intervals quite tightly.

As an extra measure you may wrap the entire roll in a foil or plastic. This will keep the moisture in and not let more in. Each slight variation may give different effects.

Step #5 Steaming (or boiling)

Depending on the type of leaves you have used they may give off odd smells/vapour when they are steamed/boiled. I have read that sumac may be somewhat irritating to some. For that reason I decided to do the cooking outside on the BBQ side burner. Use an old pot or dedicated vessel.

You have the choice of steaming or submerged boiling. I chose to use steaming since it seems like less extra water would effect the print. Make sure the bundle is elevated (on top of some small mason jars or steam basket) and you don’t run dry. You can add metals to the water as extra mordant but I feel that they don’t really get into the bundle when steaming.

The time needed also varies. Some boil/steam for as much as 3 hours and some for about 1.5 hours. I tend to steam for about 2 hours. If you would like extra setting you can leave it bundled for a long time (weeks) or open right away. I chose something mid way. After steaming for 2 hours I wrapped them in a thick blanket to hold heat for a while longer.

UPDATE: As of late I am often using my ‘Alternate Eco Print Processing’ method and it works great and saves so much energy

Since there is generally no indication how things are going it is like Christmas when it is time to open them up. This one was giving me a bit of a sneak peek. I never tire of the opening stage! I bet that is why most find this art form so addicting.

Well, there you have it! I was quite happy with these results!

The amount of detail that these prints made was quite amazing. ‘Like stipple drawings of leaves.

These are walnut leaves were also dipped in iron solution prior to steaming. I love the detail!

Step #6 Neutralize and Wash

After unwrapping you should give them a rinse in a weak baking soda bath to neutralize the iron.  Then wash in a ph neutral detergent like (good for the duckies) ‘Dawn’ or other specialized washing soap. I find there may be a bit of extra tannin washing out, but most of the strong blacks stay put quite well.

If you have too much ‘black’ print then you have a strong iron solution and can dilute it more next time.

So, are you amazed yet!? That is just one simple basic method. There are many more variations, add in some natural colours by using a dye bath with plant dyes and you will be even more amazed how truly magical it is!

Eco Printing Method #2

‘The Iron Blanket’

As a variation of the application of the iron mordant you can also make an ‘iron blanket’. An iron blanket is an extra piece of fabric (even paper towels) that is soaked in the rusty iron water and then wrung out. This layer will be put above the leaves to bring the iron to the fabric in a different way. In this method the leaves are not dipped in iron water, they are used as is (or wetted if dried)

Do you notice a difference in how the colours/prints turn out here? They are now printing the colours outside of the leaf shapes since the iron is applied around the leaf shape. The tannin of the leaf spreads out from the leaf and blends with the iron from the blanket to create the ‘halo’ shape and accent the leaf. Some make soak through the leaf and also print a colour. You just never know exactly…

The Barrier Layer

To keep the colours from bleeding through the layers I definitely use a barrier layer. That can be plastic wrap (Like Saran wrap) or strips of plastic drop sheets (reusable). Some find success in using baking parchment paper, even tin foil as a barrier. I like to use the drop sheets as I can cut off a strip in the width that I am working with.

This is a heavy weight cotton that was pre-mordanted with soya milk. It is soaked in a solution of soya milk and water ( 1 part to 5 parts) and dried and then repeated. This can be repeated as many as 5 times. I soaked in soya 2x.

The results are again quite amazing! I love how they look like water colour paintings! Each specie of leaf can also bring some colour to the mix.

Oh how I wish I could grow some eucalyptus leaves! Go ahead, run out and get some leaves and Eco Print on Cotton. Do check out here before you start on your magical Eco Printing journey. Natural dyes add another dimension (cochineal, pomegranate, logwood, sumac )

Have fun creating botanical prints, so many variables, easy instructions. More complete info here

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101 Comments

  1. I am quite late to this post, but so intrigued by this process! My question is about the iron water. Do you have a ratio estimate of iron water to plain water in the tub with the leaves? Thank you! Your site is just fantastic!

    1. That’s always the question. I tend to be quite heavy with my iron as you see these are almost black. When using rusted pieces it’s quite an estimation. If you buy Iron Sulphate it is better to measure. Many factors can influence the outcome so I generally work like an artist, by ‘feel’. If dipping fabric you can weigh it and then use 1% (more or less) iron in a bucket. Some leaves ‘want’ more iron to print some less. Best way; test your leaves, water differences can also influence. But do mordant/prepare the fabric properly. I love these prints using maple

  2. Hello!! I’m trying to apply this technic for my thesis (it envolver sustainable ways of producing fashion garments), I’ve made multiple attempts and I don’t know what I’m doing wrong.

    I do believe that my issue is the mordant. I didn’t have time to make it as you with the rusty stuff and wait 2 weeks (have a deadline). So I used the iron sulfate suggestion. But I still can’t make it happen. The flowers and leaves look like they lost all coloring but it doesn’t stick to the fabric. And I did go throu the cleaning process of the cotton.

    Please help.

    1. Not all the leaves have the ability to print. Maple, sumac, rose are reliable. Flowers tend not to print as the tannins are not there. Also cotton is more difficult than silk. Make sure it is indeed 100% cotton. The best mordant for cotton is Aluminum acetate. Check this post

  3. Thank you for sharing this captivating info! I was wondering using the “iron blanket” technique, if I were printing on silk can I use cotton as the iron blanket or vice versa? I’m assuming some color may transfer to the cloth used as the “blanket” so I want to use a unimportant/inexpensive piece of fabric for that. Do you know?
    Thanks again!

  4. Thank you so much barb! I have a question regarding the premordant process, because in my case I have a hemp-silk fabric. 60%hemp-40% silk, what would you recommend? Sending love your way!

    1. Well, cotton is a fibre made from plants and a tree is a plant so it may work. I know birch leaves can print grey so they have some tannin and maybe the bark does too… There’s so many tests that can be done to discover new ways to eco print. It works well on paper so I’d give it a shot. But, please do not rip it off live trees as it can damage them badly 🙏🏻

  5. Barb, thanks so much for all the sharing!! When you say after wash with baking soda, what percentage of WOF would it be? Take care!

  6. I tried steaming inside with just eucalyptus and had a headache so bad I almost called an ambulance. Since then I never steam inside.

    1. I would soak over night, wring out and let dry. It can be repeated to build the layer that will then act somewhat like a protein fibre. Some eco printers like to give it time to cure as well.