Best mordants for eco printing fabric

Hi Creative Mamas! Welcome to another great article about eco printing on fabric and natural dyeing.

In this post I want to talk about the best mordants for eco printing and how different mordants will provide you with a different and unique result.

If you know me and my work, you will know that I only use mordants which are safe for me and for the environment. I like to have a sustainable craft practice and part of that is choosing certain materials and staying away from others.

an eco printed cotton shirt using onion skins, pansies and marigold flowers

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Different mordants for eco printing

To ensure good results, you must consider the type of fabrics as well as the type of plant material and natural dyes that you are using before choosing the mordant.

There are many plants that you can use in eco printing but there are a lot that are no good as well. so here is a list of the best 30 leaves and flowers that you can use in eco printing for great results!

Download the FREE Eco Printing BEST leaves and flowers by completing the form below

Note: You need to work with 100% natural fabrics, so make sure to do a fabric burn test to ensure your fabrics are all natural.

Choosing a mordant for eco printing fabric

Even though eco printing is a very experimental practice, there are a few variables that you can rely on.

If you are using a wool fabric you will need to use a mordant which is appropriate for protein fibers and if you are printing on linen you must use a mordant that works well with cellulose fibers. (This applies to all natural dyeing practices as well).

Also, if you want the tannin of certain leaves to react with iron you would use an iron based mordant… so, with these variables in mind, I want to suggest a list of the best mordants to use for eco printing.

This list is not exclusive, it’s a list of the mordants (which come in the form of fine powders) that I feel get the best results consistently when used in eco printing.

The eco prints shown in the photo below were all created by using the suggested mordants and are part of the step by step La Creative Mama Eco Printing Video Course.

a variety of different eco printed techniques in different types of fabrics and colors

Alum Sulphate

Alum sulphate is the go to mordant when it comes to dyeing and printing with protein fibers such as silk and wool.

Alum sulphate doesn’t color the fabric which makes it a great mordant to use with eco printing. The white areas will remain white and the leaves and flowers will create defined prints.

The photo below shows a piece of silk which was printed by mordanting with alum sulphate using a dye blanket (cochineal) and eucalyptus and liquidambar leaves.

In this case I was going for a positive/negative type of print.

a piece of silk printed using a dye blanket from cochineal dye

Alum tends to give a yellowish tone to the prints compared to other mordants.

Alum Acetate

Alum acetate is the go to mordant for cellulose fibers such as cotton, linen and paper.

As with alum sulphate, this mordant will not color the fibers.

The photo below shows the results of an avocado leaf and a marigold flower printed on watercolor paper using alum acetate as a mordant.

eco printing on paper to make paper cards

The photo below shows the results of a piece of cotton printed with liquidambar and eucalyptus leaves which were dipped in iron water.

a piece of fabric printed using iron dip, eucalyptus and dyer's chamomiles

As you can see, Alum acetate doesn’t dye the fabric either so it’s great to use in combination with iron dips and dye blankets as well.


Tannin is a natural mordant and a natural dye. therefore, the fabrics will acquire a beige/brown color once they are mordanted in tannin.

I use tannin mordants in combination with iron blankets as shown in the photo below. I used oak leaves, coreopsis flowers and silver dollar eucalyptus.

Tannin is a great mordant to use with cellulose fabrics and an iron blanket.

a cotton fabric eco printed with tannin mordant and iron blanket

It’s also a great mordant to use with protein fabrics. The photo below shows a piece of habotai silk which was mordanted in tannin and combined with a dye blanket (logwood).

a silk fabric eco printed with tannin mordant and iron blanket as well as logwood blanket

Ferrous Sulphate

I like to use ferrous sulphate (or iron powder) as a mordant to create darker prints. The print below was made in silk fabric using ferrous sulphate mordant.

a piece of silk mordanted with iron printed with silver dollar leaves and pansies flowers

You can create your own iron solution at home as well by using rusty nails.

Iron mordant and alum

Sometimes I like to combine alum and an iron solution in the mordant bath to create a particular effect.

The photo below shows a cotton shirt which was upcycled using eco printing.

I decided a wanted a copper /blue theme so I combined iron and alum to accentuate the pansies’ blues to transform the yellows of the marigolds into coppers.

an upcycled cotton shirt eco printed with onion skins and marigold flowers

Upcycling with eco printing

Eco printing and natural dyeing are both great ways to upcycle and transform old clothes and fabrics.

The following blog posts (tutorials) have detailed instructions on how to make great tote bags and t shirts using eco printed fabrics.

Check out the eco printed drawstring bag which was made from eco printed silk fabric using an iron dip technique.

Also you may enjoy this eco printed cross shoulder bag. The fabric is silk and was printed with a dye blanket using onion skins.

And this is a super cool bag which was made out of silk which was printed using a dye blanket from cochineal and eucalyptus leaves.

Note: The blankets are immersed in the dye bath before using them in the printing process). You can make dye blankets from a variety plant dyes such as avocado dye, tea dye and onion skins.

My favorite upcycle project is this eco printed cotton fabric t-shirt because it was made in winter and it represents the winter colors surrounding me here in New Zealand.

an upcycled cotton fabric shirt eco printed with eucalyptus leaves

You may also enjoy how to make silk scarves using bundle dyeing in a dye pot.

9 thoughts on “Best mordants for eco printing fabric”

  1. Hi Victoria,
    what a fantastic amount of information!
    I have a question- what mordant would you use on a 75% cotton 25% silk fabric? would it be a mix of Aluminium sulphate and aluminium acetate?

    • Hi Denise, good question!!!! I would go with alum acetate since cotton seems to be the highest component in the mix 🙂 Hope this helps

  2. Hi! Can I use black tea as a mordant? Cause if I dye sth with tea the color will last, but what would happen if I mixed black tea with tumeric? Would that be enough to make the color last more? I know it would of course change the color of the tumeric to darker

    • Hi Noemi,
      I think its really worth doing it, I have sometimes mixed turmeric with other dyes to create a brighter color and they have stayed really bright over the years, however every time I wash the fabric some turmeric still bleeds, but the color is still beautiful so I would definitely try it, also be mindful that tea will give you a dark brown by itself 🙂

  3. I’m new to eco-dyeing & printing & I want to tank you for providing such a wealth of information. The photos are great for illustrating the points you make as well.

  4. Hello Victoria
    I am very much looking forward to experimenting.

    I am in Tasmania Australia, and wondered if you can suggest a site where we can buy all of the main supplies please, eg: Alum acetate, alum sulphate, ferrus sulphate, logwood extract etc

    thank you

    • Hi Shaah,
      Yes! I always recommend kraftcolour to my autralian friends, which is based in Melbourne, they have everything you need! Hope this helps!


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