glas jar filled with a white substance, sitting on a wooden surface

Cold Water Mordant: Aluminium Triformate

Today I want to share a simplified mordanting method with you: using the cold water mordant aluminium triformate. Aluminium triformate has numerous benefits compared to other mordants which we will explore in detail in this post.

Table of Content:


If you want to learn more about mordants for natural dyes, you can check out this video on my Youtube channel:

a hand holding a spoon with a white substance and several dye materials in the background. a text saying mordants for natural dyes.

What is aluminium triformate?

Aluminium triformate (also known as aluminium formate) is the aluminium salt of formic acid. It comes in the form of a white powder. It is commonly used to clean wastewater, tanning leather, and preparing paper [1]. When it comes to natural dyeing, aluminium triformate can be used as a mordant.

glas jar filled with a white substance, sitting on a wooden surface

What is mordanting?

If you have never dyed a skein of yarn or a piece of fabric before, let’s start at the beginning. Mordants are essential if you are dyeing either protein or cellulose fibers with natural dyes. A mordant or dye fixative is a substance which is used to set dyes on fibers. It forms a coordination complex with the dye which attaches to the fiber. As a result, mordants enhance the wash- and lightfastness of the dyed yarn or fabric.

When it comes to choosing a mordant, there are several options available. They can generally be grouped into metal-salt mordants (like alum) and plant based mordants (like tannins). I have written a blog post all about different types of mordants which you can find here: What is a Mordant? (Mordants for Natural Dyes).

Benefits of using aluminium triformate as a mordant

But what makes aluminium triformate stand out among the different types of mordants you can use for natural dyeing purposes?

Reason #1: Versatility

One of its major benefits is the fact that aluminium triformate can be used for both protein (wool, silk) and cellulose (cotton, flax, hemp) fibers.

Reason #2: Energy Consumption / Ease of Use

But there is more. Another advantage of using aluminium triformate as a mordant is that no addition of heat is required, meaning the mordanting can be done at room temperature. Not only does this mean that you need less energy in the form of power consumption, it is also an easier process. You simply make the mordanting solution, immerse the fiber in it and you are done. You don’t have to check the temperature and give it a stir from time to time. After a couple of hours (or even days, depending on your schedule), you take the fiber out of the mordant bath and it is ready to use!

How to mordant with Aluminium Triformate:
Step-by-step Tutorial

1. Safety precautions

Don’t use the same pots and utensils for natural dyeing that you use for food preparation. Always wear gloves. Creating the mordant solution should be done in a well ventilated area. Do not ingest. Do not breathe dust. Wear protective gloves, safety goggles and a dust mask when handling fine dye powders and mordants.

2. Calculating

Aluminium triformate can be calculated as either grams per Liter (gpL) or weight of fiber (WOF).

Option #1: gpL method

100 g aluminium triformate can be used to mordant up to 1,5 kg of cellulose fibers (cotton, linen) or 3 kg of protein fibers (wool). You will need 5 liter of water for 100 g aluminium triformate, this creates a 2% solution.

Option #2: WOF method

The second option is to calculate the amount of aluminium triformate you need based on the amount of fiber you want to mordant. The recommended amount is 5-10% WOF. For example, if you want to mordant a 100 g skein of yarn (3.5 ounces), you will need 5-10 g of aluminium triformate.

3. Step-by-Step Tutorial

  • On the first day, scour the yarn or fabric thoroughly in a bucket filled with room temperature water. Gently press the fiber under the water surface and make sure that it is fully immersed in the water bath.
pot with water, soap dispenser and an undyed hank of yarn
  • Day 2:

    Option A: Gpl method:
    Measure 20 g of aluminium triformate using a scale and add it into a pot filled with 1 liter of lukewarm water (122 F / 50 °C max). Stir with a metal or wooden spoon until the powder is fully dissolved.

    Option B: WOF method:
    To mordant a 100 g skein of yarn (3.5 ounces), measure 5 g of aluminium triformate. Add the mordant in a pot filled with lukewarm water (122 F / 50 °C max) and gently stir with a metal or wooden spoon until the powder is fully dissolved.

    Take the yarn or fabric out of the water bath and gently wring it out. It should be wet but not dripping. Add the fiber to the pot containing the mordant solution and make sure that it is fully immersed in the mordant bath. Leave the fiber in the pot for at least 8 hours.
    The time period can be extended without any issues. You can leave the yarn or fabric in the mordant for days, but I usually leave it just overnight.
undyed cream skein of yarn in a pot with water
  • If you are ready to proceed with the natural dyeing process, take the fiber out of the mordant bath. Gently squeeze out the excess water, give the yarn or fabric a quick rinse and you are ready to go.

4. Reusing the mordant bath

When choosing the GpL method, you can reuse your mordant bath multiple times. In the example above we created a mordant solution that can be used for up to 300 g of cellulose fibers (cotton, linen) or 600 g of protein fibers (wool) (using 20 g of aluminium triformate and 1 liter of water).

Color Comparison: Aluminium Triformate vs. Alum

On the picture you can see two skeins of yarn (a blend of 85% wool, 15% linen) that were dyed with madder. The left skein has been mordanted with aluminium triformate and the right skein has been mordanted with alum. There is no significant difference in color intensity visible.

two hanks of naturally dyed, orange-red yarns on a wooden background

Want to learn exactly how to get started dyeing yarn with natural dyes?
This free guide for beginners walks you through the eight steps of dyeing a skein of yarn using natural dyes.

four hand dyed skeins of yarn in shades of purple and blue on a wooden surface and a text saying beginner's guide: www.rosemaryandpinesfiberarts.de. natural dyeing. everything you need to know to get started dyeing yarn with natural dyes

Pin It For Later: Cold Water Mordant: Aluminium Triformate

a glass jar filled with a white substance sitting on a wooden surface and a text saying the easiest way to mordant yanr & fabric, www.rosemaryandpinesfiberarts.de

Further Reading:

[1]         https://www.dharmatrading.com/dyes/aluminum-triformate.html

Annika

I am a yarn dyeing artist, writer and educator.
I am also an avid knitter and love to create something with my hands every day.
Read more about me here:
https://www.rosemaryandpinesfiberarts.de/about-the-writer/

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1 Comment

  1. Cecilia n says:

    Dear Anikka, where in Europe we can get the aluminium triformate? Do you have a link or maybe a suggestion? Thank you in advance, Cecilia.

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