4. BioChromes¶
"Colour is life; for a world without colour appears to us as dead. Colours are primordial ideas, the children of light."
Inspiration¶
- Natural dyeing in Morocco
- Ancient tradition of natural dyeing in Peru
- Forest dyeing - a natural dyer’s getaway - Maiwa
- Kathryn Davey - A Dublin-based natural dyer and author known for her gentle, experimental approach to plant colour, teaching others how to work slowly and sustainably with nature’s palette.
More inspiration¶
- Julie Beeler - An artist and educator known for her work with natural pigments, especially mushroom and lichen-based dyes. She explores the intersection of ecology, colour, and craft, documenting living palettes from the forest.
“Colour from the Land” - The Story of Natural Dyeing in Ireland¶
Dyes and Dyeing in Medieval Ireland and Scotland
Before factories, before chemistry labs and neon threads, Ireland’s colours came straight from the land. In cottages tucked between green hills and wild coastlines, pots once simmered not with stew but with oak bark, lichens, and heather...
Before factories, before chemistry labs and neon threads, Ireland’s colours came straight from the land. In cottages tucked between green hills and wild coastlines, pots once simmered not with stew but with oak bark, heather, lichen, and gorse, the ingredients of Ireland’s first colour alchemists.
Long ago, dyeing was considered a near-magical craft. Stories in early Irish folklore warn that dyeing in the presence of men could spoil the colour, as if the wool itself sensed the wrong kind of gaze. Women gathered their pigments from the hedgerows and bogs, using what the seasons offered: ivy berries for green, dock roots for rusty reds, blackberries for violet, and the bright sunshine of gorse flowers for yellow. Even the sea played its part, gifting seaweeds that yielded soft browns and olive tones.
When trade routes opened, ships brought madder for red and indigo for blue, expanding the island’s natural palette. By the 1700s, Dublin’s Weavers’ Guild kept the city alive with texture and tone, and small mills dotted the countryside. Colour was part of life, as essential as the wool itself.
But when synthetic dyes arrived in the 19th century, the old ways nearly vanished, the dyepots grew cold, replaced by easy, factory-made hues.
It wasn’t until the 20th century that the tradition began to stir again. Visionaries like Lillias Mitchell at the National College of Art & Design brought the craft back into classrooms, founding the Irish Guild of Weavers, Spinners and Dyers to keep these skills alive. Their students learned not only technique, but reverence, that colour is something alive, responsive, and deeply local.
Today, the dyepot has found new hands. Artists like Kathryn Davey and a growing community of makers across Ireland are once again foraging, experimenting, and re-discovering what the land can give. From the wild gorse of Howth to the lichens of Connemara, Ireland’s natural dye story continues, a living dialogue between craft, ecology, and memory.
It’s not just about making colour. It’s about remembering where colour comes from.
Research¶
Old stories about natural dyeing is found in the folklore collection:
Old Crafts – Dyeing (Dúchas: Loughkeeren)
In search of forgotten colours¶
This is a compendium of four short films with English subtitles.
Sachio Yoshioka (master dyer) is the fifth-generation head of the Somenotsukasa Yoshioka dye workshop in Fushimi, southern Kyoto. When he succeeded to the family business in 1988, he abandoned the use of synthetic colours in favour of dyeing solely with plants and other natural materials. 30 years on, the workshop produces an extensive range of extremely beautiful colours. He is also a color historian: part of his practice involves researching old Japanese texts, traditional colour names, and dye recipes from the Heian / Nara eras to revive lost shades.
Biochromes¶
Biochromes are biological colours, natural pigments created by living organisms. The word comes from the Greek bios (life) and chroma (colour).
They’re nature’s own dyes, inks, and paints, colours grown, not manufactured.
A biochrome is a molecule that absorbs certain wavelengths of light and reflects others, giving colour to plants, animals, fungi, and even bacteria.
Value¶
The Natural dyeing process¶
Materials Needed¶
Fibres¶
- 100% Cotton (plant fibre)
- 100% Wool (animal fibre)
- Silk (animal fibre)
Natural Dye Sources¶
- Safflower
- Madder
- Chinese Rhubarb
- Cochineal
- Weld
- Alkanet
- Logwood
- Indigo
- Onion Skins
- Black Beans
- Marigold
- Hollyhock
- Coreopsis
- Other natural dyestuff (see dye table)
Tools & Equipment¶
- Hob / Heat Source
- Pots with Lids
- Beakers & Containers (various sizes)
- Sieves
- Spoons, Ladles & Tongs
- Weighing Scales
- Thermometer
- Mortar & Pestle
- Scissors & Ruler
- Labels / Paper Tape
- Camera (for documentation)
Chemicals & Mordants¶
- Sodium Carbonate (Soda)
- Aluminium Potassium Sulphate (Alum)
- Iron Sulphate
- Copper Sulphate
- Citric Acid
- Vinegar
- Ethanol
- Water
Preparing Fibres: WoF, Scouring & Mordanting¶
Before dyeing, fibres must be cleaned (scoured) and treated (mordanted) to properly absorb colour.
Weight of Fibre (WoF)¶
- Fabric: 150 g
- Wool: 100 g
- Divided into 16 pieces of approx. 10 g each
Scouring Cotton (Plant Fibres)¶
Purpose: Remove oils, waxes and residues so fibres can absorb dye.
Steps:
- Soak cotton fabric in clean water
- Heat a pot of water
- Add Sodium Carbonate and mix
- Add soaked fabric
- Maintain temperature & stir occasionally
(Avoid boiling plant fibres too harshly)
- Scour for at least 1 hour
Cellulose Mordanting - Triacetate Bath (Cotton/Linen).¶
Recipe – 500 ml Bath
- 500 ml Vinegar
- 50 g Aluminium Sulphate
- 25 g Sodium Carbonate (added slowly)
Steps:
- Blend vinegar + aluminium sulphate
- Add sodium carbonate bit by bit
Stop if mixture turns white → over-saturated
- Blend until dissolved (no fizzing).
Neutralising (Fixing the Mordant):
- Prepare: 2 g Percarbonate in 2 L cold water
- Rinse fabric after scouring
- Dunk fabric into triacetate bath (fully saturate)
- Brief hang → then dip into percarbonate bath
- Hang to dry before dyeing
Mordanting Wool (Animal Fibres)¶
Purpose: Bind dye to protein fibres
Mordant Formula
- Alum: 15% of WoF
e.g. 15 g Alum for 100 g Wool
- (Optional) Cream of Tartar - pinch (for softness & shine)
Steps:
- Pre-soak wool in hot water (releases oxygen)
- Heat fresh water in pot
- Dissolve alum + cream of tartar
- Add wool gently (no agitation - avoid felting)
- Stir occasionally
- Mordant 30–60 min
- Allow wool to cool in pot
- Dry, divide into dye portions
- Re-wet before dye bath
Natural Dye Bath Guide¶
Each recipe below is based on the given Weight of Fiber (WOF). Adjust recipes proportionally based on your fiber weight.
General Notes¶
- WOF = Weight of Fiber
- pH Reactive Dyes: Citric acid (acid) or soda carbonate (alkaline) can shift colours
- Ethanol Extracts: Use >86% purity
- Strain dye baths before adding fibre
- Do not boil animal fibres
Alkanet Root¶
150% WOF → 45 g
Solvent: 500 ml Ethanol (≥86%)
Steps:
1. Weigh 45 g alkanet root.
2. Cover with 500 ml ethanol in a sealed jar.
3. Extract for 24–48 hours, shaking occasionally.
4. Strain pigment into dye pot.
5. Optional: Add hot water to extend bath.
6. Adjust pH:
- Citric acid → purple tones
- Carbonate → blue-grey tones
7. Add pre-mordanted fibres and heat gently.
Madder Root¶
200% WOF → 60 g
Steps:
1. Weigh 60 g madder root.
2. Rinse briefly to remove dust.
3. Add to warm water to rehydrate.
4. Heat slowly to 40-50 °C (do not boil).
5. Maintain for 1 hour.
6. Strain before dyeing.
Chinese Rhubarb¶
150% WOF → 45 g
Water: 150 ml
Steps:
1. Weigh 45 g rhubarb root.
2. Add to 150 ml water.
3. Heat to simmer (70–80 °C).
4. Optional: Add chalk to reduce acidity.
5. Strain and dye.
Safflower¶
130% WOF → 40 g
Steps:
1. Weigh 40 g safflower petals.
2. Cover with cold water – discard yellow liquid.
3. Repeat rinses until water runs clear.
4. Add fresh alkaline water (carbonate) for pink extraction.
5. Keep bath under 40 °C.
6. Soak fibres without heat.
Weld¶
45 g
Steps:
1. Weigh 45 g dried weld.
2. Cover with hot water to rehydrate.
3. Heat on stove to gentle simmer.
4. Optional: Add chalk.
5. Strain and dye.
Hollyhock¶
45 g
Steps:
1. Add 45 g hollyhock to water.
2. Heat gently to extract.
3. Strain plant matter.
4. Dye fibres (acid vs alkaline shifts).
Marigold¶
45 g
Steps:
1. Weigh 45 g marigold petals.
2. Simmer gently (max 60 °C).
3. Strain.
4. Dye fibre.
Coreopsis¶
23 g + one handful
Steps:
1. Combine 23 g + one handful of flowers.
2. Add to water and bring to low simmer.
3. Steep 45–60 min.
4. Strain and dye.
pH Modifier Effects¶
| Modifier | Effect on Colour |
|---|---|
| Citric Acid | Brightens, pink/yellow |
| Soda | Darkens, blue/grey |
| Chalk | Brightens yellows |
Our natural dye colours¶
Our shared documentation for dye recipes & outcomes1¶
Lake Pigment Guide¶
Making pigments from natural dyes
Lake pigments are created by binding dissolved natural dyes to a mineral base, forming a solid pigment that can be dried, ground, and used in paints. This process “captures” the colour permanently.
Add to your dye bath, add 10grams of Alum & 5grams of Soda:¶
The precipitation:¶
Drain the mixture:¶
The pigments:¶
Materials & Equipment¶
Fibres & Dye Liquor¶
- Use strong, filtered dye extraction (from plants such as madder, weld, logwood, etc.)
Equipment¶
- Heat-safe beaker or stainless pot
- Stirring rod or spoon
- pH strips or pH meter
- Thermometer (optional)
- Coffee filters / filter paper & funnel
- Scale (accurate to 0.1 g)
- Trays or plates for drying
- Mortar & pestle
- Gloves, labels, containers
Chemicals¶
Alum Route (most common)
- Aluminium Potassium Sulphate (Alum)
- Sodium Carbonate (washing soda) or Sodium Bicarbonate (baking soda)
Optional: Calcium Route
- Calcium Chloride
- Sodium Carbonate
Basic Ratios (Starting Point)¶
- 200–500 ml strong dye liquor
- 2–5 g alum per 100 ml dye
- 10% soda solution (10 g soda ash in 100 ml water)
- Target pH: ~7.5–8.0 for precipitation
Step-by-Step: Making an Alum Lake Pigment¶
Filter the Dye¶
- Brew dye and strain out all plant matter.
- Filter using cloth or coffee filter until clear.
Warm the Dye (Optional)¶
- Warm to 40–60 °C to encourage precipitation (do not boil).
Dissolve Alum¶
- Weigh 2–5 g alum per 100 ml dye.
- Add directly to the warm dye and stir to dissolve.
Add Alkali to Precipitate¶
- Prepare 10% soda ash solution.
- Add drop by drop, stirring constantly.
- Watch for the milky cloud — this is the pigment forming.
- Stop around pH 7.5–8.0 (avoid >8.5).
Settle¶
- Leave for 1–12 hours (overnight recommended). Pigment sinks to bottom.
Decant & Filter¶
- Pour off clear liquid carefully.
- Filter pigment sludge through paper or cloth.
Wash the Pigment¶
- Rinse with clean water until neutral pH (~7) and no soapiness.
Dry & Grind¶
- Spread on tray and dry completely (air dry or < 60 °C).
- Grind to fine powder with mortar & pestle.
- Store in labelled jars.
Alternative: Calcium Lake Method¶
- Add Calcium Chloride solution to warm dye.
- Add 10% soda ash slowly to form calcium carbonate precipitate.
- Proceed with settling, filtering, washing, drying as above.
- Result: chalkier, warmer-toned pigment.
Using Your Lake Pigment¶
| Binder | Use For |
|---|---|
| Gum Arabic | Watercolour / Gouache |
| Egg Yolk | Egg Tempera |
| Oil | Oil Paints |
| Acrylic Medium | Acrylic Paint |
Troubleshooting¶
| Problem | Solution |
|---|---|
| No precipitation | Add more alum or increase heat |
| Too alkaline (slimy) | Add a dash of vinegar or dye liquor |
| Weak colour | Use stronger dye or re-lake again |
| Filter clogging | Add alkali more slowly next time |
Bacterial Biochromes¶
Lab Notes¶
Objective¶
To culture pigment-producing bacteria (biochromes) on agar plates, in order to explore natural colour creation for textile applications.
1. Preparing the Growth Medium (Agar Mix)¶
- Measured nutrient agar powder.
- Mixed with distilled water in a heat-resistant flask.
- Stirred thoroughly until fully dissolved (no clumps).
- Optional: Checked and adjusted pH if needed.
2. Sterilisation - Autoclaving¶
- Transferred agar solution into autoclavable bottles/flasks.
- Loosely capped to allow steam release.
- Autoclave settings:
- 121°C
- 15 psi
- ~15–20 minutes
- Purpose: Eliminate any possible contaminants.
- Allowed medium to cool slightly but remain liquid before pouring.
3. Pouring Petri Dishes¶
- Performed inside a sterile environment (laminar flow hood or disinfected bench).
- Poured warm agar into sterile petri dishes (approx. 3–4 mm depth).
- Left plates slightly open to set and release excess condensation.
4. Inoculation with Bacteria¶
- Wiped down the work area with ethanol.
- Used a sterile loop or swab to apply bacteria.
- Streaked or dotted bacteria onto agar surface depending on test.
- Labelled plates with:
- Bacterial strain
- Date
- Medium type/experiment code
5. Incubation¶
- Placed plates upside-down in incubator.
- Incubation temperature: ~25–30°C
- Monitored daily for pigment development and contamination.
6. Aim of Biochrome Experiment¶
To observe how bacterial pigments can be harvested or transferred to textiles using: - Direct growth on fabric - Contact transfer (fabric laid on colony) - Agar stamping or diffusion methods
Observation Checklist¶
| Observation Area | Notes |
|---|---|
| Colour Intensity | Deep or pale pigmentation |
| Diffusion Pattern | Rings, spread, or local spots |
| Texture | Glossy, matte, wet, dry |
| Contamination | Presence of unwanted growth |
Next Steps¶
- Test fabric contact with agar plate.
- Explore colourfastness on natural fibres (cotton, silk, hemp).
- Record changes over time (oxidation, darkening, etc.).