FROM SEEDS TO BLUE - WORKSHOP 1 - FRESH LEAVES INDIGO.
1 JAPANESE INDIGO SALT RUBBING METHOD
Japanese Indigo Fresh leaves extraction on silk using the salt rubbing method. In September 2023 with children from Jordanhill S1
Japanese Indigo fresh leaves extraction is one of the fastest way to share how plants and colours are connected.
This week is about creating blue colour out of home-grown plants:
Woad and Indigo are pretty much the only plant material in the Botanical world that will give you a natural blue colour and they are used in so many cultures to that effect in different ways. From the pigment extraction in India to the fermented leaves of the Japanese Sukumo the blue pigment is used to dye fibre. The methods are very varied but the principle is always the same.
It is a matter of using the ingredients from the leaves to extract a pigment which then in transformed into a dye. During its life the Indigo colour will take the solid and soluble format a few times. What makes a successful dyeing is to understand how to manipulate this pigment to obtain at the right time pigment or dye.
In this short section we will just touch the tip of the iceberg that is Indigo dyeing but we will learn to get some interesting blues out of our leaves in quick easy methods
Unlike with other dye plants, the colour/pigment blue comes from the leaves but is not immediately present in its ready to use format.
In fact, the leaves contain what we call "precursors". In other words what will become indigo pigment after processing. We call the plants different names but the actual colour is the same Indigo pigment once it is formed and it works the same way. To complicate things once you have extracted this pigment from the plants… you have to transform it into a dye to be able to use it.
No wonder a lot of Indigo lovers are very overwhelmed when starting with Indigo dyeing. But really it is very simple. Taking the fear out of the process is really the first step of any Indigo learning.
In its pigment form Indigo can only be used to make watercolours or printing paste. In order to dye with it you have to reduce it… in other words take out the oxygen molecule from it and turn it into a dye.
In this week's sharing we will do just this with our Woad plants in a vat format, and our Japanese Indigo leaves with easy fresh leaves methods.
With the Indigo leaves we will dye straight from the precursor stage without allowing the precursor to become pigment… Many use the Salt rubbing technique but few understand what they are dying with. It is a great method but can only be used in small quantity.
We will also use the Iced method which allows us to work with larger quantity of fabric and because a lot pigment will be left in our iced bath, we will then reduce this liquid into a dye vat by taking out again the oxygen in the reduction process.
What we will achieve:
- Achieve a variety of blues depending on how much pigment has be secured on our cloth
- Learned about extracting the pigment
- Learned about using the precursor of the Indigo pigment
- Learned about reducing the Indigo pigment into a vat
What methods we will work with:
- Japanese Indigo Salt rubbing method (direct transfer of colour to fibre)
- Japanese Indigo Iced method (direct transfer of colour to fiber in larger quantity)
- Reduction of the Iced bath of Japanese Indigo into a vat (larger and darker dye bath)
ABOUT JAPANESE INDIGO FRESH LEAVES, THE SALT METHOD RUBBING METHOD:
Your Indigo plants should take a couple of months maximum from planting in the grounds till mature.
One quick way to access if your leaves are ready would be to pick one and crush it in your hand. If it turns blue it is ready… Another way would be to use the leaf bashing method. You sandwich a leaf between say to layers of thin fabric and using a large but flat stone or a hammer you bash it to make an imprint. When you expose the print to air if it turns blue you have pigment.
Our first method will allow you to get blue from your leaves even if they are still at early stage.
Salt rubbing method with fresh leaves (pigment from leaves no reducing agent)
Salt rubbing method on a variety of fabrics using Japanese Indigo (left) and Woad (right)
FOR THIS METHOD YOU NEED:
Up to 200 grs of Japanese Indigo picked leaves (only pick when you need and don't pick what you are not just about to use).
Some cooking salts
A non-reactive bowl (so plastic or stainless steel are perfect).
Some gloves like latex in case you have some skin cuts.
Some clean protein fibre. I suggest fine silk gives the best result but you can get some kind of result even on the toughest fibre.
You will have to work fast with this one as the pigment will start oxidising as soon as liberated and you will only have a short window to catch the colour. I think it is fair to suggest 10 to 15 minutes at the most and the colour from your leaves will be oxidised into pigment. At this stage the "juice" will still be there but will not dye any more.
This is a very simple technique that just needs salt rubbed into the fresh leaves. That will open the leaf cells and the Indicant precursor chemical and enzyme in the leaf plus the oxygen will join forces to create blue Indigo on the fibre you are dying.
Japanese Indigo leaves ready for the Salt rubbing method.
- Start manipulating the leaves with the salt then add the textile but no water needed.
- The leaves will become a mush like welted spinach and the colour will escape onto the fibre. This will take a few minutes (a maximum of 15 mns). When the colour coats the fibre and air kicks in the Indigo precursor turns into pigment and fixes the colour onto your fibre.
- It is possible to repeat the same process for several loads of leaves for a very dark result or just the one time for a light blue.
- Rinse the piece under water to help oxidising and remove any leave bits or yellow colour that would have escaped from the leaf.
- If you want your piece darker you could then start again with a new batch of leaves.
- This is a very quick and satisfying method to do on fine silk and to share with new to dyes people, especially children.
- Wash your piece with a little gentle soap.
- Dry your silk to observe the final colour obtained. It will be a good few shades lighter.
- Because you are working directly with the leaves, originally you will add some of the other pigment/colour available in your leaves in your fabric such as Chlorophyl but if after washing you hang your pieces in the sun to bleach them they will become bluer from a kind of sea mermaid green/blue.
In the method as you have not added any alkaline agent to your process there is no need for a vinegar rinse.
The leaves can be added to the compost pile in both account as they are just leaves without any chemical agent added.
This liquid left over can be rinsed in the sink.
Your hands might be a little blue if you are not using gloves but they will wash really well it will not last.
You could compare the difference of shade of blue between your Woad vat and your Salt rubbing method. Same pigment but very big difference in the amount of pigment involved.
2. JAPANESE INDIGO ICED BATH METHOD FOR DYEING AND VAT MADE FROM THE RECYCLED ICED BATH
This second tutorial about using your Fresh Japanese Indigo leaves to create blue material is about creating darker blues in slightly larger pieces of fabric and is also suitable for small quantity of wool.
I have recorded a video to show you what we will do and how it will create different shades of blue. There is good learning there so I hope that you will enjoy it even if you are not ready to dye for now.
REVIEW THE VIDEO HERE
The fabric used for this will be still in the format of squares and could be for up to 50 x 50 cms in size. You will be able to dye linen (for the vat) but the first method The Iced bath will give you much better results with silk fibre.
You will need:
- A container preferably transparent for hosting your iced bath, it would need to be of a non reactive material (plastic or stainless steel).
- A bowl (I use a stainless steel) one and a large piece of mesh (I use organza, I have some recycled silk organza, the dye colours the silk as well as gets strained in it) Some clamps to attach it to the edges of the bowl.
- A blender of some sort. There is no staining and no chemical in this process so you could use a domestic blender.
- Some gloves
- Some ice cubes
- Some cold water
- A way to rinse and dry your cloth.
- A variety of silk pieces, you could try small skeins of wool (and cellulose if you really want to try).
- Some Japanese Indigo leaves (Woad does not work for this).
Then…
- A stainless steel pot with a lid to make the vat
- A hot plate or an induction plate
- A thermometer
- Some Soda ash
- Some Thiox, Spectralite
- Some Ph paper.
- A stainless steel spoon to stir the vat.
- Some fabric, a variety of but must be natural material, cotton, linen, silk, skein of wool.
Rinsing space, drying space.
How to proceed:
1 - ICE METHOD:
- Harvest around 200 gr of Japanese Indigo leaves (one stem has around 25 gr of leaves), it is better to repeat this several times to allow for colour to build up than do one large quantity at the same time. Because the liquid will oxidise if you make a large bath you will have a large quantity of liquid that has not been used.
- Peel the leaves from the stems. You can place the stems in a jug and after one week they will have roots. You will be able to plant them into the garden for more harvest after a few weeks.
- Please the leaves in a container with some very cold water and ice cubes, and blend until the leaves are completely cut up. Stir a bit and then stain the mix through the mesh fabric you organised over a ball. Squeeze the enormous teabag so to get most of the liquid out.
- At the same time you will have prepared your fabric by soaking it ready to dye.
- Start dyeing by introducing your rang fabric into the dye liquid slowly without adding any oxygen and manipulate it slowly to give it an even cover. If you leave it untouched and one piece folds over you will have marks.
- Leave your fabric for say 3 minutes and take out to oxidise. Ring, open and move around to allow it to become blue fast. As soon as it is blue it can go back in for a second dip. Each dip will make your fabric darker.
- You could try with a selection of fabric, and various number of dips.
- BEWARE YOU ONLY HAVE AROUND 20 MINUTES FROM WHEN YOU START BLENDING TILL THE BATH IS OXYDISED.
- When oxidised transfer the liquid to your stainless steel pot and start again with new fresh leaves.
In this method you are dyeing with the precursor of the Indigo dye. By moving your fabric around as it has been dipped in the Indigo Liquor, you are injecting Oxygen and creating a pigment lake on your fabric. This will fix it.
When happy with the result… rinse in clear water.
As there are no chemicals you do not need to do a vinegar rinse for this process.
2 - VAT METHOD WITH THE ICED LIQUID:
- Add all the iced method liquids into your dye pot and make sure you have no plant material left as they will be staining your fabrics when reduced.
- Heat up to around 50 degree CC. Test the Ph using your testing papers. The Ph should be very acidic because this is mainly fresh plant material around may be 5?
- Add a small quantity of Soda ash to the liquid to make the solution alkaline. Soda ash is one the ingredients you can use for this. You could use Lime or Calcium hydroxide or Amonia, or even bicabornate of Soda, but we choose to use Soda ash because it speaks well with the Thiox of the synthetic vat.
- Your ph should be now around 11/10 and that is a good moment for reducing your vat using thiox/Spectralite/colourremover
- Use around 15 g/20 gr for up to 20 litters of liquid that you sprinkle on the top of the vat.
- Use spoon to stir well into the dye liquid creating a vortex into the vat. Close the lid and keep warm for around 1 hour. This should create a strong vat that will give really dark blues…
- Unless you are dyeing wool there is no need to keep the vat warm. You can take it off the heat.
- Dye your fabric in the vat together with all the various "bit" you have been reserving. They should be wet before they go into the vat.
- Use the timing of 3 minutes dip/2 minutes to oxidise. The vat will keep working well until it has ran out of colour.
- Because you are using a very alkaline agent here you will need to use a vinegar bath to rinse your fabrics.
- When happy with your various shades of blue you can just rinse three times in clear water, Leave in the vinegar bath for 30 minutes and thence last rinse into the clear water.
Your dyed fabric will be securely dyed and ready to be admired or to process with your yellow dyes for green.
The key point with the vat is to keep the Ph around 9/10, below that the Indigo is not properly reduced and could just rinse off your cloth.
Indigo should not bleed if it is dyed well and your finishes are completely done.
No comments:
Post a Comment