4. BioChromes

This week we had the opportunity to experiment with a variety of techniques, including Shibori and ink, using natural materials such as indigo.. and I loved it! We produced vibrant natural colours while exploring fibre compositions and their reactions to different dye applications.

Research & Inspiration

Current fashion and societal trends drive high demand for textiles, often resulting in severe environmental impacts, as shown in River Blue (2017). Industrial dyeing processes contribute to water pollution and resource depletion.

MORE SUSTAINABLE APPROACHES ARE POSSIBLE!
The following concepts and examples have been a source of inspiration for my research on this theme.

I believe the words in _wovenwomen, an Instagram profile devoted to crafts, capture the essence of natural dyes beautifully. Credit: Instagram

Capucine's Books guided and inspired us during this week:
- Dominique Cardon - Le monde des teintures naturelles: A landmark study exploring the history, science and cultural heritage of natural dyes.
- Marie Marquet – Guide des teintures naturelles : Plantes à fleurs: a practical guide to over 100 flowering plants used for natural dyeing.

Artisans and artists:

• La Robbia is an artisanal studio in Sardinia, that explores natural colors through local dye plants, such as Anchusa crispa (Sardinian bugloss), Armeria sardoa (Sardinian thrift) and other endemic Mediterranean species that reflect the island’s biodiversity.
  

• Bacche Rosse is a botanical dye project by Erika Bozzi, who cultivates her own dye garden in southern Italy to craft naturally colored textiles and host immersive workshops on slow, plant-based making.
  

• Rhyannan Hall is a UK-based artist specializing in Arashi Shibori, a Japanese resist-dyeing technique. Her textile artworks have been shown internationally and she runs workshops promoting craft-based practices.

• Marga Creation is a french atelier of vegetal colors that come to life poetically on fabrics, wood and paper.
  

Credits: La Robbia - Bacche rosse - Rhyannan Hall - Marga Instagram

Fabricademy Alumni:

• Capucine Roberts for sharing some recipes and providing her samples in our lab.
  
• Charlotte Bracho and Isobel Leonard for inspiring with the organization of the samples.
  
• Elsa Gil for the colorful images and graphic contributions in explaining the process.
  

Final results and colour charts

Personal photo of my final samples

I am creating colour charts on A4 paper to display all our results, organized by colour. Diana and I will also prepare a copy for the lab. More updates coming soon!

Below is an overview of all fabrics and colors after dyeing, displayed on the lab table. We were really happy with the final results here at the Lyon lab :)

Credit: my photo

Four silk shawls in brilliant colors, dyed with natural pigments from logwood (campeche), indigo, madder, and acacia. Credit: Capucine Robert's photo

Final considerations about materials:

• The dyeing on the wool worked really well, which makes me very happy, especially since the Lyon lab is part of the EU Woolshed and we work a lot with wool here.
  
• Silk scarves gave us bright color.
  
• Cotton is the one that has absorbed the least of the ingredient.
  

Final considerations about techniques:

• Natural dye is so powerful, I appreciated the time it took to process it, the ability to transform waste into a resource.
  
• Iron has given us amazing results, especially with materials with tannin properties.
  
• I would definitely like to experiment more with Indigo and Shibori technique.

Natural Dyeing process

After an introduction by Capucine during which we also got to admire her experiments with wool and samples of her Fabricademy, Diana and I were introduced to the process,we worked together this week.

Credit: Capucine Robert's photo

The process is mainly composed by the following steps:

1. Selecting fabrics and dye matter
   

2. Calculating WOF
   

3. Scouring
   

4. Mordanting
   

5. Preparing Dye Baths
   

6. Dyeing and Drying
   

7. Modyfing colors with Iron
   

1. Selecting fabrics and dye matter

We decided to work with 12 type of cotton, linen, silk and wool and with 6 ingredients as dye matter.

Credit: my photo

As ingredients, we selected a combination of fresh materials, extracts, and dried galls, in order to achieve a rich mix of colours.

Credit: my photo

Ingredient	Buddleja leaves	Carrot tops	Logwood	Madder	Acacia	Oak galls
Scientific name	Buddleja davidii	Daucus carota	Haematoxylum campechianum	Rubia tinctorum	Acacia spp.	Quercus spp.
Source	Collected around the lab	Local market	Lab	Lab	Lab	Lab
Form	Fresh	Fresh	Extract	Extract	Extract	Dried
Expected colour	Yellow	Yellow	Purple	Red	Brown	Green

We cut all the fabrics into three samples so that, at the end of the process, each of us would have one (one for me, one for Diana and one for the lab). The only exceptions were a few silk scarves and an embroidered cotton piece, which we kept whole. We then sorted all fabrics according to the colouring ingredient.

Credit: my photo

Fabric/Ingredient	Plant leaves	Carrot tops	Logwood	Madder	Acacia	Oak galls
Silk pieces	x	x	x	x	x	x
Silk scarf			x	x	x
Linen	x	x	x	x	x	x
White cotton	x	x	x	x	x	x
Beige cotton	x	x	x	x	x	x
Shibori cotton			x	x	x x	x
Embroidered cotton		x
Cotton yarn	x	x	x	x	x	x
T&M carded wool	x	x	x	x	x	x
T&M felted wool	x	x	x	x	x	x
T&M yarn wool	x	x	x	x	x	x
Brown yarn wool	x	x	x	x	x	x
Grey yarn wool	x	x	x	x	x	x

T&M = Thônes e Marthod (breed of sheep).
A long list of fabrics and colours, definitely a lot to do!

2. Calculating the weight of fibre (WOF) and ingredients

Using a scale we weighed fabrics divided by color, we obtained WOF (weight of fibers).

Then, following Capucine's instructions, we determined the percentage of each ingredient required to act as a dye.

Note: In cases where the recommended range varied (e.g., madder: 1–10% for pale red, 10–30% for strong red), Diana and I selected the percentage according to the shade we wanted to achieve.

Finally, we calculated the exact amount (in grams) of each ingredient needed according to the WOF, using the formula: WOF × % of dye material.

Ingredient	Plant leaves	Carrot tops	Logwood	Madder	Acacia	Oak galls
WOF (g)	39	154	49	49	51	47
% of dye material	300%	300%	15%	10%	16%	50%
grams of dye material (g)	120	362	7.35	4.9	8.2	23.5

3. Scouring

Cleaning fibres before dyeing is important to remove natural oils, waxes and impurities, ensuring that the fibres can absorb dyes and achieve brilliant colours.

Cellulose fabrics (cotton and linen): it is necessary to apply a specific dosage of cleaning agents, which are Natural Soap and Sodium Carbonate, based on WOF.

Other animal fibres (wool and silk): a small amount of natural soap is sufficient.

STEPS

1. Weigh cellulose fibres, without separating by colour this time, and calculate the quantities required. In our case, WOF = 234 g
   

2. Apply these proportions for cellulose: Natural Soap: 20% of WOF -> 20% x 234g
   Sodium Carbonate: 6% of WOF -> 6% x 234 g
   

3. Prepare three pots and washed fibers based on parameters in below table.

4. When the washing time was up, take out the fibers and fabrics and leave them to dry.

Table with our parameters:

Textile	Natural soap	Sodium carbonate	Washing time	Water temperature
Cellulose	46.8 g	14.04 g	2h	warm (~40–50 °C)
Silk	3g	-	1h	lukewarm (~30–35 °C)
Wool	3g	-	1h	warm, not boiling (~35–40 °C)

Maintaining the right water temperature is essential for all fibres.
Wool, for instance, may shrink or become felted if exposed to excessive heat.

Credit: my photo

4. Mordanting

In this step, fibres were treated with a substance (called a mordant) that helps the dye bind (from the Latin mordere) to the material, it improves colour intensity and durability.

MORDANTS USED THIS WEEK

• Alum (Potassium Aluminum Sulfate): the most widely used, safe for both cellulose and protein fibres.

• Iron (Ferrous Sulfate): darkens or “ages” colours, giving greys or muted tones.

• Cream of Tartar (Potassium Bitartrate): an acidic additive, often used with alum on protein fibres.

• Calcium salts (salt): minor modifiers, can slightly change tones or improve dye absorption on protein fibres.

STEPS

1. Separate all the fabrics associated with oak galls, as this material contains natural tannins that act as a mordant.

2. Measure the pH of the water, in our case was 8, slightly basic, which can affect how mordants react with different fibres.
   

3. Add animal fibers (silk + wool) in a pot and cellulose fibers (linen + cotton) in another one, as they required different mordants.

4. Immerse the fibers in their respective baths and heated them on the stove for 1h (80 degrees), allowing the mordants to fully penetrate the fibers. Stir occasionally to ensure even absorption.

5. After cooling, rinse the fibers.

Mordants and dosages used based on fibers and pH of the water:

Material/Mordant	WOF	Allum	Creme tartar	Sodium carbonate
Cellulose	330g	66g (20% WOF)	16.5g (5% WOF)	6.6g (2% WOF)
Animal fibres	334g	66.8g (20% WOF)	-	-

Extra: Shibori technique

Shibori is a traditional Japanese dyeing technique that involves folding, twisting, binding, or stitching fabric before dyeing it, usually with indigo, to create intricate patterns.

We tested this technique on 5 pieces of cotton, one already lightly colored.

The results weren't always satisfactory (colors were too light, knots weren't perfect), but we tried. Only in two cases did we use knots we knew, we'll study further!

Credit: my photo

5. Preparing the Dye Baths

Once the ingredients have been weighed based on WOF on step 2, we left them to soak or dissolve for at least 12-24 hours before dyeing.

ACTIONS:

• Cut the Buddleja and carrots leaves into small pieces and place them in two separate containers, then added water to each for maceration.
  

• Place the extracts (powdered) in separate containers and add water to dissolve.

• Mix the oak galls finely, but dont' add water until the next morning. This ingredient requires a maximum of 4 hours of maceration.

Credit: The photo on the left is by Capucine Robert

The following day, for the Buddleja and carrot tops, we followed the Decoction Method:

STEPS:

1. Place the ingredient in separate pots.

2. Add water and heat on the fire, keeping the temperature around 80–90 °C for about 1 hour.

3. Filter the liquid to remove the plant matter and keep the coloured water.

4. Return the bath to the pot and let it cool down slightly.

6. Dyeing and Drying

Once the baths were ready, it was time for the dyeing!

We filled each pot with a color and immerse related fibers, warm gently on the fire for 1–1.5 hours, stirring frequently.
We ensured fibers were fully covered with liquid and if not, we added water.

Credit: Capucine Robert photos

The above process excluded the oak galls. This specific dye bath was heated for 1 hour without the fabrics. The fibres were then added off the heat and left to soak for another hour.

After the time had passed, we gently squeezed the fibers and left them to dry.

7. Modifying Colours with Iron

Iron sulfate, in addition to being a mordant, is a natural colour modifier. When added to a dye bath or used as a post-dip, it darkens and shifts hues: turning yellows into greens, reds into purples or browns, and, in the presence of tannins, transforming light shades into dark tones.

We tried it with all our post-dyeing materials with a 10% concentration, following the recipe below.

PROCESS

Ingredients:

• 100g Iron (sulfate)
• 1L Vinegar

• 50g Sodium carbonate Place the ingredient in separate pots.

• Mix all the ingredients but be careful when adding the Sodium Carbonate as it blows up.

• Dilute the solution with a max. concentration of 10%, otherwise it will damage the fibers. In this case, dilute 100mL of Iron 100% in 900mL of water (at room temperature).

• Add your fibers to the concentration solution, color should change in some seconds.

• Remove and let them dry.

Although some colours initially seemed unlikely to work, once we left the fibres to air-dry, they produced amazing results!

Credit: my photo

Exploring Indigo and its Blue

Completely unexpectedly, Lise, a friend of Pauline's, arrived on Friday lunchtime with fresh indigo leaves. She grows the plant in her home garden and told us we had to act quickly if we wanted to extract the blue color from the leaves.

We followed a recipe she gave us and immediately tried dyeing wool, cotton and silk.

MATERIAL & STEPS

Material:

• Indigo leaves (the upper ones color more)
• a pot filled with water at room temperature
• a handful of coarse salt
• fabrics and fibers (we used some extra ones)
  

Steps:

1. Add salt to the water and chop and squeeze the leaves with your hands inside the pot.
2. Add your fibers and rub and squeeze them against the leaves. Continue for 5-10 minutes. You can repeat the rubbing process even out of the water for better coloring. We did it and it worked!
3. Wash fibers with natural soap and water.
4. Let the fibres dry naturally, the air will help the colour develop.

Credit: Capucine Robert's photos

Credit: my photo

The fabric that worked best was silk, followed by wool (although it is more difficult to remove the leaves).

Inks

With part of the leftover dye bath from Madder and Logwood, we experimented with making inks, following the recipe below.

MATERIAL & STEPS

Material:

• Dye baths
  
• Gum arabic
  
• potassium alum, vinegar, sodium carbonate, iron sulfate
  
• small containers
  
• sheets of paper
  
• brushes
  

Steps:

1. Add Gum arabic to the dye bath
   
2. Add small amounts of potassium alum, vinegar, sodium carbonate, iron sulfate to each small container
   
3. Try different mixtures obtained on sheets of paper with brushes and get different colors!
   

We prepared a sheet for each of us and an extra one for the lab.

Credits: Capucine Robert's photos

Credit: my photo

Colour Patterns

Capucine and Pauline wanted to experiment with a natural dyeing technique, called Aluminum Acetate Stain Technique.

It is used to create a paintable mordant paste that can be applied directly onto fibres or fabrics. This paste allows to draw or paint patterns, which will later fix dyes more precisely, giving control over where the colour will appear on the fabric.

The process to work with is made up of 4 main phases:

1. Preparation of the paste
   

2. Coloration for visibility
   

3. Application on fabric
   

4. Setting and Finishing with Wheat Bran Bath
   

MATERIAL & STEPS

Material:
Aluminum acetate (mordant): * 200 ml vinegar * 20 g alum (potassium aluminum sulfate) * 10 g sodium carbonate

Paste: + 2 g guar gum

To paint: * cotton fabrics (already scoured) * brushes * sponges

Steps:

1. Combine the ingredient to form a paste. The alum acts as the mordant, the soda adjusts the pH, and the guar gum provides viscosity so the mixture can be applied with a brush or other tools.
   

2. Add beetroot to the paste so it's easier to see while applying. This colour is “fleeting”: it does not permanently dye the fabric but allows to see the pattern during application.
   

3. Apply the paste onto pre-washed fibres or fabrics. The paste can be painted, stamped, or drawn to create patterns, motifs, or designs.

4. Immerse the fabrics in a wheat bran bath: warm water for about 10 minutes, gently moved in the bath and then rinsed. This treatment serves to remove the guar gum from the paste while setting the mordant onto the fibers. Repeat this bath after dyeing in order to clean and stabilize the final colors.
   

Credit: my photo

Expected Results:
The areas where the paste is applied will absorb and fix the dye more strongly, creating defined patterns (similar to batik or stencilling).

Temporary colouring (like beet juice) helps to visualize the pattern during application, but it will fade during the fixing and washing stages.

Our Final Results:
The background was supposed to be completely white, but since we used intense colors like Logwood (purple) and Madder (red), it's understandable that this result is more difficult to achieve.
We're still satisfied and will try the technique again with other dye baths!

Credit: my photo

Towards a Circular Approach

During the lecture, Cecilia Raspanti showed us a chart she had prepared on a zero-waste approach to natural colours, which I found extremely useful for learning how to reuse and transform dye baths.

Credit: Cecilia Raspanti's photo

For this reason, I saved the colours obtained from extracts and oak galls for future testing and projects, such as creating pigments, as we didn’t have time to do so this week.

Unfortunately, the dyes made from fresh materials, such as leaves and carrot tops, had to be discarded, as they quickly developed mold and an unpleasant odor.

These four bottles were saved for future projects: Madder, Oak Galls, Logwood (Campeche) and Acacia.

Credit: my photo

Tools

• GIMP
• Canva
• TinyPNG