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4. BioChromes

INDEX IMAGE ~ Eucalyptus leaf

Lecture and Research

This week we are studying how to harness biochromes from plants, animals, fungi, minerals and microorganisms for textiles. There is a focus on low and zero waste methods to color fibers in the most efficient and sustainable way. Since I have experience with the natural dye extraction process already, this week I am especially noting these tips for reusing materials and recycling liquids.

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Natural dyes only work on natural fibers (the ones highlighted in green on this chart of total global fibers). This week we are working with silk, viscose, cotton and wool. Silk and wool are examples of Protein Fibers meaning they come from animal sources. Cotton and viscose are Cellulose Fibers that come from plant sources (bacteria can also produce cellulose and this is called microbial cellulose).

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Physical Tools

  • Scale
  • Pots, pans, strainers
  • Spoons and Stirrers
  • Ph strips


Barcelona Foraging Archive

A fun way to explore a new city is by learning about its flora ecosystem. I went on a few naturalist walks around Barcelona, taking photos of plants I thought might work for dye and identifying them with Plant Identifier later. I also looked aorund at what people have marked already on an app called Inaturalist.

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Of course I want to be as respectful as possible when forraging so I have not picked any plants as I am still researching. I love to follow this piece by Anna Tsing and another, The Honorable Harvest by Robbin Wall Kimmerer when taking naturalist walks and foraging. Some of the basic principles are:

  • never take the first plant or the last
  • ask for permision and listen for the answer
  • use everything you take
  • share it with others

Here are a few plants I started cataloging. Petra and I spoke about further developing a map or guide!

Material Name Part usable for dye Location Spotted
Yarrow leaves and flowers Parc del Centre del Poblenou
Pine needles Parque del Poblenou
Dock leaves and seeds empty lot near my apt.
False Yellowhead roots and flowers empty lot near my apt.
Rosemary leaves Emma's house
Nettle leaves Parc de Montjuïc

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Local Foraging Resources

One Recipe from our Biopantone - Eucalyptus 02

  • 32g Eucalyptus
  • 0.54g Alum
  • 0.045g Iron
  • 0.7g Silk swatch
  • 2.2g Cotton swatch
  • 1.6g Viscose swatch
  • 2.26g Sodium carbonate

Species Info

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Also known as "Baby Blue" and "Silver Leaf Mountain Gum" is a small shrub of the Myrtaceae family with long branches, flowering in spring and summer Source. It is often sold at floral stores because of it's strong aroma. I bought a bundle at Herbs florist in Barcelona.

Fiber Prep

First we make sure our fibers are clean and reasy to absorb dye. We scoured all of the cellulose fabric in a pot with 2% WOF sodium carbonate, simmering for an hour. For the silk we washed it in mild water with soap. We weighed the dry fabric to calculate mordants later on.

Dyestuff Prep

We weighed the material and found it was 32g. We added the leaves to a pot of water and let it soak for an hour. We were comparing the color made by another kind of eucalyptus (labelled 01) so this photo shows both pots. Then we brought the pot to a boil and let it simmer for another hour. The leaves soaked in the pot overnight. We strained the leaves out and the remaining liquid was a bright green color.

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We used two different mordants: Alum and Iron. A bundle of three swatches together weighed 4.5g and we used that number to calculate 0.54g alum and 0.045g iron to use. We seperated the dye liquid into two baths and added one mordant in each.


We added the fabric to each pot with the mordants and brought them to a boil. Then we simmered for an hour.
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Final Results

describe what you see in this image For the two silk swatches on the right, I used a pre-mordanting technique that I am used to in my personal work:

  • measure the dry silk
  • clean the silk with soap and mild water
  • measure alum at 15% WOF
  • dissolve the alum in a pot of water and add the silk
  • leave for 45 minutes on very low heat
  • move the silk to the dye bath and leave for an amount of time depending on how saturated you want the color to be

Here are a few more examples of colors made with this method:
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Recycling Dyes into Pigments

In order to save these precious natural colors, the left over dyebath can be turned into a dry pigment. This can then become a paint, a colorant for biomaterials, or reused as a bath later.

  • Left over dye bath
  • 18g alum
  • 6g sodium bicarbonate


  • dissolve 18g alum in hot water
  • pour it into a container with the left over dye
  • over a bowl (because this fizzy chemical reaction can get messy) slowly add the sodium bicarbonate to the container and stir
  • pat down the foam and leave for a while
  • pour the mixture into a coffee filter over an empty container
  • once strained, the colorful cream/foam substance in the filter can be placed in a dehydrator to create a powdery substance
  • dehydrate at 40C for 24 hours

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Making Inks

Here I've just included a personal ink/paint recipe for textiles I have used before. I mordant the fabric following the 'premordant alum instructions' and then apply the paints. I wait a day and then rinse it off, careful to not smear the lines.

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Bacterial Biochromes

Physical Tools

  • Petri dishes
  • Camping gas and alcohol,
  • Gloves, masks, labcoats
  • Innoculation loops
  • Pressure cooker
  • Incubator

Creating a Sterile Bubble

  • Wipe the table down with alcohol
  • Pour alcohol in a circle around the gas tank
  • Light the gas tank
  • Operate within the circle, don't keep petri lids open for long
  • Bring jar lids and innoculation sticks up the the flame to sterilize before and after pouring

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Using the Pressure Cooker "Autoclave"

  • Add water in the pressure cooker (2cm in bottom)
  • Put plastic bag inside and then whatever objects to be sterilized in the bag
  • Keep lids slightly unscrewed
  • Tilt the big bottles or fill the pot so they cannot fall over during cooking
  • Twist the bag to close
  • Put on the lid and twist it closed, make sure it is shut
  • Make sure the twist latch on the top is pointed towards shut
  • Cook for “carne” meat setting
  • Add 30 mins
  • When you open it, twist the top latch with a tool to not burn your hands, let out the steam
  • Be careful not to put your face over the hole

Plating and Innoculation

We are using two types of "food" for our bacteria: Agar and LB nutrient broth. Agar powder is mixed with distilled water, sertilized and then poured into the plate. Once this is cooled (in a jelly form) bacteria can be swabbed on to the agar and the plate is left in the incubator. In our case, we had fabric in the plate and poured the liquid LB broth over it before innoculation.

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Other Notes for Best Practice

  • Use parafilm to shut all Petri dishes
  • When you see white on the agar in the incubator it means the tempurature is too high
  • Place dishes upside down in the incubator when growing bacteria directly on agar

Biochrome Results

We experimented with the bacterium Janthinobacterium Lividum and silk. We agreed that the samples could have spent more time growing in the incubator but we decided to take them out anyway to see the results before the global review. For future experiments, we would like to try naturally dyeing silk swatches with plants, sterilizing them, and then growing bacteria over to see how they respond or how the colors look together. describe what you see in this image describe what you see in this image describe what you see in this image The final result

Our Final Biopantone

describe what you see in this image describe what you see in this image describe what you see in this image See our final collective research here

Further Bacteria Dye Tests

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Last update: 2022-12-07