Alum Mordant for Wool
Weigh your dry fabric. Take a note of it on your documenting sheet. Wet out your wool while you prepare your mordant. This should be at least 1.5 hour, and even more.• Calculate 20% WOF of Alum. • Calculate 5% of Cream Of Tartar. • Dissolve both in a non reactive pan with hot water, stir until fully dissolved. • Top up with enough cold water to cover your fabric. • Squeeze your wool gently, and open it before putting it in the mordant. • Work the fabric gently in the mordant and then let it sit overnight,
The wool should not be bulked up but be able to float more or less freely
Wetting out Fabrics
Before any mordanting, dyeing or printing, we must always fully wet out our fabrics.
Wetting out means there are no dry spots left in the fabric at all, and this can take from one hour to 24 hours.
It is important to take plenty of time for this, even if the fabric appears wet, it does not mean it is fully wet inside the fibers. Dry spots and air pockets in fabric will cause uneven uptake of mordants and dyes.
Wetting Out Fabrics
This is how I do it;
Take a bucket with plenty of cold water and a teaspoon on Ph neutral dishing detergent.
Detergent functions as a surfactant. A surfactant reduces surface tension. Reducing water’s surface tension makes it easier for the water to penetrate the fabric.
Work (knead) the fabric in the water and let it soak for at least 3 hours. I personally soak overnight. Make sure no fabric sticks out.
Wring or squeeze fabric well, rinse, squeeze again and immediately proceed to mordant, print or dye.
With wool: be gentle with turning and squeezing the fabric so it will not felt.
A word about mindful use of mordants (and other resources)
Mordants, fabrics, water, heating water, all are resources and as part of my philosophy, I wish to be mindful with those resources.
I measure my mordants carefully according to weight. All recipes have been optimalised to get maximum result with the least amount of mordant.
I save on energy by mordanting cold. I could mordant in 90 minutes by heating the water, but I have found that mordanting cold, overnight, is working just as good.
I make sure my mordants are dissolved in a bit of hot water, and then I top up with cold water and work my fabrics well into the mordant water. Then I just let it sit overnight.
The order of mordanting:
- Weigh dry fabrics and note the weight on paper.
- Scour fabrics if needed. Use a bran bath if you only need to remove sizing of handwoven fabrics.
- Weigh mordants in % according to the WOF of the goods.
- Wet out fabrics completely before mordanting.
- Dissolve the mordant.
- Mordant the fabric sin the mordant bath: heated will take 1.5 hour. Cold mordanting will be best overnight.
- Remove the fabrics, squeeze and rinse.
- Dung if you want to.
- Use or dry and store.
lum Mordant for Silk
For silk, weigh your dry fabric. Take a note of it on your documenting sheet. Wet out your silk while you prepare your mordant.
- Calculate 20% WOF and measure the potassium aluminium sulfate.
- Dissolve in a non reactive pan with hot water, stir until fully dissolved.
- Top up the concentrated alum with enough cold water to cover your silk.
- Squeeze your wetted silk out well, and open it before putting it in the mordant.
- Work the fabric well in the mordant and then let it sit overnight,
The silk should not be bulked up but be able to float more or less freely.
When on time constraint you can slowly heat your mordant to 50ºC and keep this heat for at least an hour while stirring constantly. Let cool down in the mordant pot
m Mordant for Wool
Weigh your dry fabric. Take a note of it on your documenting sheet. Wet out your wool while you prepare your mordant. This should be at least 1.5 hour, and even more.
- Calculate 20% WOF of Alum.
- Calculate 5% of Cream Of Tartar.
- Dissolve both in a non reactive pan with hot water, stir until fully dissolved.
- Top up with enough cold water to cover your fabric.
- Squeeze your wool gently, and open it before putting it in the mordant.
- Work the fabric gently in the mordant and then let it sit overnight,
The wool should not be bulked up but be able to float more or less freely.
When on time constraint you can slowly heat your mordant to 70ºC and keep this heat for at least an hour while stirring constantly. Let cool down in the mordant pot.
Wool is very sensitive to thermal changes
luminium Tri Formate
a cold mordant for cotton and all other fabrics
Aluminium triformate is a gentle cold mordant that works very well with cotton. The biggest advantage is that you can leave it in the mordant water indefinitely, which is why I use a 20 liter bucket with a lid for this that I mark well on the outside.
How to use Aluminium Triformate;
Make a 2% solution with (at most) 50°C warm water. That is 20 grams of powder per liter of water.
Making 10 liter mordant (in a plastic bucket):
10 × 20 g = 200 g of Aluminium Triformate are weighed and added to a bucket with warm water.
Stir.
For smaller amounts (3-5 liter), the powder is dissolved in warm water (approx. 40-60ºC) and then topped up with cold water.
The mordant can be used immediately.
Time in the mordant;
At 50ºC 1-2 hours.
At room temperature 8 hours.
There is no upper limit for mordanting times, so you could keep your fibre in the bucket and leave it there until you need it.
The next batch of fabric can be mordanted in the same bucket. Times needed will extend each time you use up a bit of the mordant. Top up water if needed
Copper Sulfate Mordant for all fabrics
Weigh your dry fabric.
Take a note of it on your documenting sheet. Wet out your fabric while you prepare your mordant.
- Calculate 2-4% WOF and measure the copper sulfate.
- Because the WOF is so low, I use a digital scale spoon for this..
- Dissolve in a non reactive pan with hot water, stir until fully dissolved.
- Top up the concentrated alum with enough cold water to cover your fabric.
- Squeeze your wetted textile, and open it before putting it in the mordant.
Work the fabric well in the mordant and then let it sit overnight, the material should not be bulked up but be able to float more or less freely.
I never heat copper mordant, as it works so beautifully cold. You will see the next day that the water is clear of colour and the textile is a greenish blue
Ferrous sulfate for all fabrics
In natural dyeing, ferrous sulfate is used only sparingly as a post mordant for shading. In botanical printing, ferrous sulfate is an essential tool for getting clear plant prints.
The reason: the tannins in leaves combine with the ferrous sulfate and that gives shades of gray and black.
But: ferrous sulfate is very harsh on delicate fabrics especially proteins like wool and silk, so we use it in micro-doses.
For this recipe we use 1% WOF but afterwards we will combine mordants and we will go as low as 0.5%
Dunging Fabrics
In the old days, dung was used to remove excess mordant, now in a home setting we use chalk or bran. Chalk is easier and keeps longer.
Why do we dung? Removing loose, unattached mordant particles gives clearer results in printing.
Do I have to? No, it is optional.
Does this also count for silk? Yes, if you are already dunging, dung everything.
Ingredients:
10 liters of water
50 grams of chalk
How-to
Dissolve the chalk in the water, give it a good stir.
Dip the mordanted fabrics in the chalk water for two minutes.
Squeeze excess water back in the bucket.
Rinse.
Proceed to use or dry.
Make chalk dung baths in a bucket with a lid and discard after a week.
Storing Mordanted Fabrics
It is a great idea to bulk mordant fabrics in advance. Measuring out small WOF for a small piece of fabric is much trickier.
After mordanting, dung the fabric, rinse, dry and mark clearly so there will be no confusion.
If you choose not to dung, you still need to rinse your fabrics really well before drying.
I do NOT store alum mordanted silk, as I have found it becomes really brittle like that.
Personally I prefer to calculate everything a week ahead to the max, and I do not store mordanted fabrics for longer periods
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