Making lake pigments
Today I have a guest post for you written by Jule Kebelmann from Hey Mama Wolf. Jule shows us how to extract dye from plants and create a lake pigment, then use it to make our own paint. Use the paint on paper or to decorate walls. This is a beautiful way to bring the qualities of your local plants into your home.
This article first appeared in Plants Are Magic volume 4 in 2019 (retired from print).
I’m a textile designer with a love for herbs, plants and natural fibres. I brought these passions together in my business Hey Mama Wolf. We make local and sustainable knitting yarns and use only natural dyes. Painting the walls of our house in plant paints is another way for me to explore nature. Before I show you how to make these paints, let me tell you how I came to this idea.
A few years ago, my family and I moved from the centre of Berlin to the middle of nowhere, halfway to Hamburg. We were lucky to find an old water mill.
The house, which is about 250 years old, is in a general good shape thanks to its builders. Back then all the building materials came from the surroundings: boulders, stones, chalk, lime and clay from the fields, willow branches, oak trunks with wooden joints in the wooden framework, mudbricks and sand. If it wasn’t for the electrical lines and the 1970s plumbing, this ensemble of buildings would be fully compostable.
It still needs serious renovation and rebuilding. We (my man, two children and me) are doing most of the work ourselves and we make conscious choices and try to use local materials wherever possible. In three years we’ve finished just two rooms: the children’s rooms. We’re just about to begin working on our bedroom. We both work full time and have two small children so this is just the pace we have to accept. We truly embrace slowness and continue to live on a construction site!
Most of the walls are in plain chalk white but the natural clay colour is also quite lovely – it is warm and earthy so we will keep some of the walls in their natural state. My son had the idea for a ‘golden’ wall. We painted it with mica (a naturally occurring silicate) and vegetable casein as binder directly on the brown clay wall. This brought me to the idea of painting walls with plant pigments. I did a bit of research and discovered that I had everything to hand to make lake pigments and began experimenting.
What is a lake pigment?
A lake pigment is a dye combined with an inert binder (e.g. a metallic salt) to make the dye insoluble in water. We will first extract dye from plants, then combine the dye with a metallic salt in a specific way to make a lake. A dye can be dissolved in water, but a lake pigment is insoluble in water and colours materials by dispersion. The technique I use to make lakes involves alum (an aluminium salt) and an alkali like washing soda.
Which plants can we use?
You can try this technique with any plant that you can extract dye from. So far I have used avocado pits, coreopsis flowers, cherry tree bark, nettle, delphinium flowers, elder tree bark and mugwort.
Depending on the plants you use, the colourfastness will vary. In general the light fastness is not very high, but nevertheless, the paints still bring the characteristics of the plants into the home.
Take care when identifying plants and ensure they are non-toxic. Use your own judgment when following the methods to ensure your safety. Wear a mask and safety glasses/goggles when working with powders. Wear an apron and gloves to protect your skin and clothes from powders, dyes and pigments. Don’t inhale fumes from dye pots. When working with chemicals, please follow the safety instructions on the box or packet. Once you’ve used any equipment for dyeing, don’t use it in the kitchen again. Work somewhere with good air circulation, away from children and animals.
Tools + ingredients
- Large pots and glass bowls
- Spoons for stirring and measuring
- Coffee filters
- Pestle and mortar
- Plant matter and water
- Alum (potassium aluminium sulphate)
- Washing soda
- Acacia gum (gum arabic)
- Vegetable casein (legumin)
- Ammonium carbonate
1. Make the dye
Gather your fresh or dried plant matter. Put it in a large enough pot and cover with water. We don’t need as much water as for dyeing fabric or yarn because we want to make a strong solution. Let it sit overnight.
The next day simmer it for 1-3 hours to extract the dye.
Allow it to cool down or let it sit again over night. Then strain through a muslin cloth.
To make different hues from the same plant matter you can use iron vinegar or copper vinegar solutions at the beginning of the process. These will shift the colour of your dye liquid. In general, iron will make the dye darker and copper will enhance yellows.
Make your metal vinegars by soaking iron or copper pieces in vinegar and leaving them for a few weeks. Strain off the liquid and use to shift the colour of your dye.
2. Add alum
Next we’ll add alum to our dye liquid. Measure the volume of dye and make a note of this.
For every 100 ml dye, prepare 5 tsp of alum solution. To make the alum solution, alum needs to be dissolved in boiling water in this ratio: 5 tsp of alum to 5 tsp of boiling water. Set this aside.
Heat your dye solution to a simmer, then add 5 tsp of alum solution per 100 ml of your dye. This is a rule of thumb and stronger dye solutions may require more alum.
3. Add washing soda
Choose a big enough pot to continue because it will get bubbly and foamy.
Dissolve 1 tbsp of washing soda in half a cup of water. Add this alkaline solution drop by drop. Your dye should start to build foam. Stir, then stop adding the washing soda when it is all foamy.
Let it sit, but stir from time to time.
Once the foam has completely vanished (which may take some time), let the solution sit for a while longer to allow the sediment to fall to the bottom. It’s handy to do this in a glass container so you can see the layer of sediment form. When the solution has built a sediment at the bottom you can carefully spoon off the liquid on top.
Sometimes this clearer liquid still has enough colour, so be prepared for some amazements here! If it appears to be full of colour, reuse this liquid in steps 2 and 3 to make another batch.
Now prepare a container with a funnel lined with a coffee filter. Strain the sedimented liquid through the filter. It will take a while to drip through and you can add more liquid until the filter is truly full.
Then remove the filter carefully from the funnel. Open it on one side and lay flat on a prepared tray covered with cloth (these will get stained!).
Spread the wet pigment on the filter and put it in a warm place without much direct light. Allow it to dry fully.
Above and below: lake pigment made from elder bark and iron.
Once dry, crack the pigment off the filter paper into a mortar. Break it up really well with the pestle: the smaller the particles, the better. You can also use a coffee grinder to get a really fine powder, but do not use it for food preparation again.
5. Make the paint
Now that you have your pigment, you can make paint. Here are two methods:
The simplest way is to dissolve 1 part gum arabic powder in 2 parts water (or use liquid gum arabic). Then add the lake pigment and mix until you have a satisfying texture to paint with.
Another method is to make paint with ammonium casein. I used vegetable casein that has added soda already within it. Use a big enough pot as it will get foamy again. Dissolve 4 tbsp casein in 8 tbsp cold water and allow it to stand over night. On the next day dissolve 1 - 1 ½ tsp ammonium carbonate in 6 tbsp warm (not hot!) water and add it to the casein. Let it stand for about an hour and stir from time to time. When it’s a uniform compound, it’s done. Take your lake pigment and add to the ammonium casein until you have a rich coloured paste.
6. Let's paint
Now you can paint your walls or make a painting on paper. If you have white chalk walls like I do, try first painting a layer of casein to seal in the wall. The chalk is water-soluble and will otherwise lighten your colour.
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