ALUM MORDANT (Potassium Aluminum Sulphate Dodecahydrate)
~ Necessary for most plant dyes to ensure colour fastness ~

Alum is considered the safest and least harmful mordant used in natural dyeing. It helps fix dyes to fibres and enhances colour retention. What many don't realise is that Alum occurs naturally in nature, and some plants, such as Lycopodium, contain natural Alum.

Mordanting Cellulose Fibres

For mordanting cellulose fibres, please refer to our blog for detailed recipes:

• How to Mordant Linen and Cotton Fabrics Successfully – AppleOak FibreWorks

• How to Mordant Linen and Cotton Successfully Without Tannins – AppleOak FibreWorks

Basic Recipe for Wool

Ingredients:

• 10%-20% Alum (based on the Dry Weight of Fibre - D.W.F.)

• Wool (or other protein fibres)

• Water

• Optional: 5% Cream of Tartar (for hot mordanting)

Instructions:

Cold Mordanting:

1. Weigh your dry textile material.

2. Soak the dry material in water.

3. Dissolve Alum in hot water and add to a mordanting pot filled with water.

4. Add pre-soaked wool and let sit for 24-72 hours.

Hot Mordanting:

1. Dissolve Alum in hot water and add to a mordanting pot filled with water.

2. Add 5% Cream of Tartar to slow down the mordant uptake.

3. Add wool and bring to 80°C for 1 hour.

4. Let cool, then rinse and dye or dry for later use.

Alum is ideal for protein fibres like wool and silk, ensuring vibrant and lasting colour results.

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IRON MORDANT ~ Mordant, Colour Changer, increased light fastness

Iron (Ferrous Sulfate) is used alone as a mordant, influencing Colours and to increase light fastness when used in combination with other natural dyes.

Iron is best known for shifting yellows into greens, keep in mind that this is not given and doesn't work with every yellow plant dye, in which case it will be more of a brown. it is used to increase light fastness for weaker plant dyes, bu it will always sadden and/or darken the colours. 

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Basic recipe:

When adding Iron to your dye bath start of with 3% and use it at the end of your dye bath or as an after bath. Allow to oxidize for 10 min for full colour development.

*If you like your colours darker, increase the Iron amount by 1-2% at a time. 

**Leave for 10min than remove from dye bath - Iron will make wool brittle.

Sodium Acetate ~ Used to turn Ferrous Sulfate into Ferrous Acetate; used in the Mordanting Recipe for Cotton and Linen without Tannin (see below)

Sodium acetate, NaCH₃COO, also abbreviated NaOAc, is the sodium salt of acetic acid. We use Sodium Acetate to turn Iron into an easier digestible version of itself, Iron acetate. Similar to 'Iron Water' but you can control the amounts. Iron acetate is not as harsh on the fibres and can be easier digested by nature or your septic tank when turned into rust. Once made, it has no shelf life and needs to be used immediately. 

For mordanting Cellulose fibres, please choose one of the following recipes on our blog:

How to mordant linen and cotton fabrics successfully – AppleOak FibreWorks

How to mordant Linen and Cotton successfully without Tannins – AppleOak FibreWorks

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Basic recipe: 

1part Ferrous Sulfate

1part Sodium Acetate

Mix and dissolve in Water. I find that it makes the iron stronger and we only use 1% of Iron acetate on most recipes. Warm water will also intensify the reaction.