4. Biochromes

color cloud In one of the most inspiring weeks so far, we dived into the world of colors and all of it's unexplored forms.

Color, say what?

I find it interesting how certain things just belong to our lives for such a long time that we don't even know how to classify or fully understand but yet get totally impacted every single moment by it. Color is one of those things, before documenting this week process I wanted to get a better sense of this particular concept and try to find words that could possibly describe what color is. A good start is this summary of a very interesting philosophical article:

Colors are of philosophical interest for a number of reasons. One of the most important reasons is that color raises serious metaphysical issues, concerning the nature both of physical reality and of the mind. Among these issues are questions concerning whether color is part of a mind-independent reality, and what account we can give of experiences of color. These issues have been, and continue to be, inextricably linked with important epistemological and semantic issues.

Maund, Barry, "Color", The Stanford Encyclopedia of Philosophy (Spring 2019 Edition), Edward N. Zalta (ed.)


While americans say color and british say colour, I decided to stick with color in this text, simply because the aestethics of the word appeals more to me. But in the search on what does define color after all, I came accross to some curious information that I would like to share.

My dear friend Wikipedia says that the Latin word color, has roots from Old Latin colos (covering), Proto-Indo-European ḱel (to cover, conceal) and some other ancient laguages sharing similar meanings. So it's already interesting to observe that color emerges as something related to coverage or concealing, which can be more associated with paint, ink or dye rather than the expression of colors in objects or nature.

Even more interesting to me, being Brazilian and a Portuguese native speaker, I realized this:

LATIN : color | DANISH : kulør | FRENCH : couleur | SPANISH : color | ITALIAN : colore | DUTCH : kleur | ENGLISH : color or colour

aaaaaannnnd PORTUGUESE : COR

Aparently our Portuguese ancestors were a bit lazy when talking latin and to make life easier they decided to cut off some consonants. So color, turned into coor, which finally became COR (Partially reliable font here - in portuguese). Now you might think, so what? Well it happens that a very commun expression in portuguese is "saber de cor" which means "know by heart" and in this context, the word cor also comes from latin meaning heart.

So I would like to think that this is not just a coincidence and because colors touch us in such a special and indescribable way, it's more related to our heart than to simply covering things.

in case you got curious the word "heart" in portuguese is "coração", probably another long story...

physics of color

dark side of the moonIconic prism at Pink Floyd's Dark Side of the Moon album cover To understand how we perceive colors, first I had to remember my physics lesson in school. A very briefly description is that different colors are actually different wave frequency of light, so depending on this frequency, humans are able to see a color or not and this determines the visible spectrum.

Human beings are only capable of seeing from ~380 to ~740 nm Wavelength interval - meaning from purple to red, before and after that we have ultra-violet and infrared respectively. visible-spectrum

However the color of an object will be determined by which light waves this object absorbs or reflects when hit by white light (the mixture of all of them), meaning that the color will be "revealed" to us are the reflected ones.

Much deeper explanations can be found on these links:

Ted Ed | Wiki | The Physics Hypertextbook

perception of color

It gets more intersting when we understand color as a sensation in our body, as we perceive color with light sensitive neurons in our retina, called cone cells. There are three types of cones, one for each of this 3 color waves: RED, BLUE and GREEN. Better then me trying to summarize all this, here is a great short video from Ted Ed:


The Fascinating History of the Color Blue

Do Women see More Colors than Men?


Artist Neil Harbisson was born completely color blind, but these days a device attached to his head turns color into audible frequencies

Mary's Room: A philosophical thought experiment - Eleanor Nelsen

Color: Physics and Perception | Pupa Gilbert

Biochromes experiments

During the past week we added a lot of new words and concepts to our vocabulary, as Loes beautifully described in this section of her documentation. So I will allow myself to source from there!

Well done girllllllll

Natural Dye

We did many experiments with natural dyes, varying from the type of yarn or fabric used and also to changes in the PH or other modifiers leading to different colors and results.

Here follows the basics steps of the process:

What to dye

Select which type of fabric or yarn to dye. Most of the fabrics are made either from an animal or a vegetal fiber. Animal fibers have a large amount of proteins and a structure that resemble the human hair, therefore they are usually easier to dye, absorving and retaining more color. While vegetal fibers are mainly made out of cellulose, because of their structure, these type of fibers not always bond well with colorants or mordants, needing extra substances to make a good dye.

In our process we used the following materials > Vegetal fibers: Cotton, Sugar Cane, Algae, Hemp, Linen, Recycled Cotton | Animal Fibers: Regular Wool, Silk & Mohair and Silk

skeins Skeins ready by Beatriz Sandini

Weight the fibers dry - WOF

After selecting all the materials to work with, make sure to have their WOF (weight of fibers) when still dry, this will be important to determine the amount of mordant will be needed.


Before dyeing you want to make sure to have the fibers clean and ready to receive the color. For animal fibers no scouring is needed, so such a simple wash with warm water and soap should be good enough. However the vegetal fibers need to be scoured. Scouring: process to remove the oil and waxes that are naturally present in the fibers. Boil the fibers for an hour in water and sodium carbonate (soda ash), ±2 spoons for 4 liter water.

For the vegetal composition fabrics, Cecilia had them pre-scoured the night before in her washing machine, at 90 degrees with sodium carbonate. For the other vegetal yarns we had, we let them boil fo one hour with water + 2 tbsp sodium carbonate


This process will add a substance called mordant to your fibers, serving as a sticky bridge between the fiber and the colorant. The most common types of mordants are: Alum, Iron and Copper. Some of them also act as a modifier, having an impact on the final color.

In this step we took the vegetal fibers out of the scouring bath and rinsed them. After this we add dissolve in the pan with water, the Alum mordant 10-15% of the WOF, then add the fabrics into it and let it simmer for one extra hour. We did the same process with the animal fibers, just being more carefull not to let it boil and also not to shock the fibers with cold water when rinsing after.

Dyeing - Adding color

After Scouring and Mordanting, the fibers are ready to get some color, the process from now on will depend on the Dye stuff each one selected to work with. I used Avocado pit and will describe how the process went with this delicious fruit.


dye stuff : AVOCADO PITS | ORIGIN PROBABLY SOUTH OR CENTRAL AMERICA (purchased in Amsterdam supermarkets) | DATE BETWEEN SEPT-OCT 2019

  • I had 8 avocado pits in my house that I've saved for a while with the intention of dyeing fabric, they were all dried and wraped in a paper away from light. The first step was then to peel off the pit skin.

avocado pit

  • I took the avocados to simmer in water in a pan, for the first 20 minutes the water had just a very light color. So Cecilia recommended to add some drops of Amonia and also a pinch of Soda Ash. After some more minutes the color started to became more visible and a beautiful pink-red shade started to come out.

avocado boil

  • At this moment I added my fabrics/yarns to the dye bath. I set the temperature to 80 degrees and let it there for about 40 minutes.


  • BATH I : Since I had already added some soda in the begging I tested the PH of my bath, which was quite neutral. I kept one of each type of fiber in the original bath and started making smaller pans to play with modifiers.


  • BATH II : PH modifier - ACID. My first attemp to get a different shade was with Citric Acid, I added little by little (diluted in water) and checking how the bath dye was corresponding. The color went to a more orangy/peach tone, I let the yarns there simmering for more 20 minutes and then kept them in the bath.


  • BATH III : PH modifier - ALCALINE. I tried to make the red more intense by adding more soda ash, but actually the color didn't change much, so I also added some Copper and got a more brownish bath (at this point I had to add some extra water to my bath, so it can be the case that the color was already too diluted)


  • BATH IV : Mordant as a modifier - Iron. In my last modify attempt I added a bit of Iron liquor and I got a bit more browninsh/purple color (very similar to the Copper one, but again a very diluted base bath)

I let all the 4 baths in pots with the fabrics/yarns inside overnight. And only removed them the next morning.





Campeche/Logwood/Blauwhout Dye

ADD PICTURES virgin bath - deep pink - got dirty with the stick and got purple add copper - deep blue from yellow to blue - shades of green orangy - with citric acid

Madder Dye

I also did some experiments with Madder, doing a base dye by simmering the root for some minutes the intense red/pink color comes very fast. By adding iron I realized the color went a bit more brownish, and later some fabric were totally orange, most likely because they weren't mordanted before with Aluin!! madder-chart

Tie-dye with Madder + Campeche experiment

  1. First folded a cotton twill fabric into a little square (in a very random form), then added to the madder bath tie-dye-0square in the bottom
  2. Then opened up, rinsed and tied in a different way tie-dye2
  3. Added the new fabric into the Campeche (logwood) bath with copper inside
  4. Removed after 20 minutes tie-dye2
  5. After rinsed and dried final

Because I did both dyes very fast the color is not so strong, but is a very interesting thing to play with.


All the Amsterdam students documented their exeperimentation on the spredsheet above. The idea is that we had a big range of different colors and could later go back to that table to find out what could possibly give which color and the PH senstiviness. Each dyestuff has its own number (from 1 -9), letters from A - N determine the yarn or fabric used, and roman numerals are used for differentiating each type of bath, varying from I -IV.

As a result we could all use the same terminology and based on Bela's design ( <3 ) create a common color chart.

Avocado shades avocado-chart


gorgeous table at biochromes week



In Search of Forgotten Colours - Sachio Yoshioka and the Art of Natural Dyeing

Ink making

get your mushrooms and come - Copper added to Alkanet in ethanol

Making inks out of natural dyes also requires a specific vocabulary/knowledge, the main concepts are listed below.

  • VEHICLE : is the liquid in which the pigment is suspended - Water, Ethanol or Oil/Gel

  • BINDER : is the substance that works like a glue between the dye stuff and the liquid, it gives more viscosity to the ink so is not spreading like water when applied to the paper - Arabic gum (it works only with water based inks)

  • ADDITIVE : is the substance that helps stabilising, intensifying, modifying, preserving or thickening the ink - Salt, vinager and metal

I decided to make different types of ink, always testing the color variation with Vinager, Soda and Copper.


For Alkanet, Turmeric, Blauwhout and Cabbage I used ethanol as a vehicle. For Madder and Avocado I used the water base dye and let it simmer for a long time so I could get a bit of ink in the bottom of the pan.



filter dirty mixed colors filters also give a beautiful result

giraffeGiraffe by Beatriz Sandini with turmeric ink, soda ash and copper splash

Bacteria Dye

Working with bacterias was a totally new and different way to see dyeing. The bacterias used to extract color and the other substances in the lab are considered Lab safety I, which is a very low level of danger, but still some precausion is needed.

  • No foods or drinks in the lab
  • No windows or doors open, so the air is not circulating around
  • Always clean your hands with etanol 70%
  • Use the lab coat (googles and gloves also recommended)
  • Make sure hair or other moving stuff, like necklace, are tied up

After checking all these boxes let's go to the step by step of reproducing colorfull bacteria and dyeing with them.

1. Get your bacteria

For our experiment we used the Serratia Marcescens, aka, SM. This bacteria is known for it's pink/red color and also for being PH sensitive. In acid enviroment the color goes towards pink and in more alcaline, red, orange and even yellow. Our goal in the experiment is to reproduce the bacteria in different mediums as well as growing them in a petri dish with a Silk cloth folded, making a co-desgin dye with the bacteria.

Serratia Marcescens Serratia Marcescens is also art

2. Prepare Bacteria Lunch

We prepared 5 different types of food/medium to grow them: * LB BROTH (LB) | liquid form | 20g - 1L * NUTRIENT AGAR (NA) | gel form | 28g - 1L * PLATE COUNT AGAR (PCA) | gel form | 23g - 1L * WATER WITH PEANUT BUTTER (WP) | liquid form | 1/2 tea spoon for ~375ml * VEGGIE AGAR (VA) | gel form | 62,2g - 1L


First step is to weight the precise amount of each food for amount of water in the bottles, mixed them inside, label the bottles and bring to sterilize.

3. Sterilize everything

  • PETRI DISH WITH FABRIC : Get the petri dishes you are going to work with, place the textile inside. We used a silk chiffon fabric and folded in different ways. Outside of the glass place some Autoclave tape and bring them inside a pressure cooker with water. Put the heat on, when the steam starts to come out, you count 15 minutes before turning off the heat. Before opening the pan, be careful to let all the pressure go out, after check if the stripes of the tape are black, which means that the right temperature x pressure was achieved. silk-medium

  • FOOD/MEDIUM BOTTLES : Repeat the same process with the food/medium bottles, just make sure not to completely close them, as some explosion might occur.

4. Sterilized bubble

To work on a safe and sterile evironment, we put etanol on the table with a camping gas fire in the middle, this creates a sterile bubble that won't allow bacteria contamination.

Cecilia's italian hands say everything

5. Plating

Get the bottles of medium from the cooker and poor them into the petri dishes (plastic little ones). To do so, make sure to be always inside the sterile bubble gas, don't talk or walk, or in my case even HOLD YOUR BREATH!

fabricademy girls doing some serious plating

6. Inoculating

After the gel medium has cooled down, it's time to transfer the existing bacterias in the new food dishes, in a process called Inoculation.

  • Get an inoculation loop, place it in the fire until it get red
  • Cool down the loop in a little corner of the bacteria dish
  • Gently scrape the bacteria on the existing plate
  • Scrape out the bacteria on the new plate
  • Add the label with the infos: bacteria name | medium | date | name - ex: SM NA 17.10 BEA
  • Close the dish with the amaaaazing Prafilm tape
  • Put them in sauna/fridge (26°) and wait a few days


7. Checiking the results

Each food gave a different result with more or less bacteria growing, NA was the best one and VA the worst. bacteria-petri

bacteria-patternnice pattern from Pauline's bacteria dish

For the silk fabric in the big glass dish, put back in the pressure cooker, add a new autoclave tape and proceed with the same sterilizing process as before. After this all your bacterias are dead :( but you have a GORGEOUS bacteria dyed cloth. bacteria-dye-fabric

8. Harvesting the bacteria color (aka killing your babies)

Grab some lab glass tubes, very thin ones, that can easily fold when heated up. Then do a L shape tip.

Then add etanol to your bacteria dishes and gently scrape the surface. The colorant will come out with the etanol and you can save that for using either as a dye bath or as a ink.


Seratia Marcescens used as a bioweapon test in the 50's