Herbal developers

Plant-based developers have been used for many years, in this article General Treegan shares 3 different herb and plant-based developers that can be used to develop silver gelatin negatives.

Writer and photography / General Treegan [born as Andrés Pardo]

Herbal developers for silver gelatin negativesHerbalism is botany applied to medicine. It comprises the extractive use of medicinal plants or their derivatives for therapeutic purposes, often for the prevention or treatment of pathologies. Herbalism holds a strong presence in traditional cultures of Mexican medicine.

The outright objective of my residency project was to formulate B&W motion picture film developers based on Mexican plants used in traditional medicine, attempt to standardize their preparation method, and to process film with them. One way to contribute to the long term sustainability of home-processing of film is to further extant research into safer and simpler non-commercial developer processes.

Why Herbalism?

Plant-based developers have been used for many years. The base developing formula used was Caffenol CM. Caffenol is currently the most famous and frequently used eco-friendly developer.

“The idea of formulating a developer based on Yerba Mate [Ilex Paraguaiensis], a typical drink where I am originally from in South American, came to me via an article about Phil Hoffman’s Film Farm. The developer not only worked perfectly, but was also economical, could be reused, and is “eco-friendly”.”

Upon invitation by LEC to be part of the LEC-CHURUBUSCO residencies, I was immediately struck by the idea to use plants, specifically, those used in the traditional medicine of the original people, to achieve the formulation of a 100% Mexican photographic developer.

The project included close and fundamental collaboration with the chemistry team at the laboratories of Churubusco Studios, achieving an interchange between science, experimentation, and art, to achieve the results outlined below. We tested these developers for stability, pH and range, and resulting density, to evaluate their effectiveness. In general, all developers have pH above 10, a level which denotes an ‘energetic’ developer.

Preparation of an herbal developer

Most plants contain the famous tannins that by hydrolysis it form an acid and a base. In general, this acid is in the phenolic group. It can reduce the silver present in photographic film so that it is feasible to formulate a developer from them.

Three extraction methods were used:

  • Boiling the plant source in water for 30 minutes;
  • Steeping the plant in hot water for a day;
  • Steeping the plant in hot water and alcohol for a day.

The differences across the results of these three methods were imperceptible, so it was decided to steep the plants in hot water for a day, as that was the easiest method to carry out.

The method is simple. The dry leaf of the plant is placed in a glass or plastic jar that can tolerate hot water. Add 650 ml of boiling water, and leave for one day. Then, filter the liquid ( with a paper or cloth filter) to remove the rough tea and plant leaves, sticks, etc. The resulting amount of liquid might be around 500 ml.

The tea-infusion can be placed in the refrigerator for use in the following days, or you can even freeze the liquid for use in later months if you are using season flowers.

For each 100 ml of resulting tea/infusion, add 8 grams of sodium carbonate and 2 grams of ascorbic acid. Some leaves absorb more water than others, so the resulting liquid may be less than 500 ml. In these cases, add boiling water to top-up to the 500 ml mark.

Recipes for herbal and plant developers

Hibiscus developer

To prepare the tea/infusion, use 50 grams of Hibiscus flower in 650 ml of water.
Tea 500ml of hibiscus tea
Sodium Carbonate 40g
Ascorbic Acid 10g
Kbr [potassium bromide] 0.5 g [optional]

Té del indio developer [Mexican Indian Tea]

To prepare the tea/infusion, use 40 grams of mixed leaves in 650 ml of water.
Tea 500ml of “Té del Indio” tea
Sodium Carbonate 40g
Ascorbic Acid 10g
Kbr [potassium bromide] 0.5 g [optional]

Arnica developer

To prepare the tea/infusion, use 20 grams of Arnica flowers and leaves in 650 ml of water.
Tea 500ml of Arnica tea
Sodium Carbonate 40g
Ascorbic Acid 10g
Kbr [potassium bromide] 0.5 g [optional]

All tests used Kodak 5302, Kodak 3378, and ORWO UP21, processed as a negative. The resulting chemical fog is tolerable if the negative is transferred via telecine or scanning. If using the negative for contact printing it is recommended to employ the potassium bromide option suggested, above.

These formulas employed a standard developer time of 12 minutes at 26ºC for all films tested in the first use, the good thing is that it could be reused. If using another film stock, development times can be obtained through comparison with other developers or through some tests.

First developer use: 12 min@ 26ºC
Second use: 16min@ 26ºC
Third use: 22min @ 26ºC
Fourth use: 30min @ 30ºC

Herbalist developers verify the power of traditional plants, demonstrating the rich cultural heritage of the original peoples of what is now Mexico.

Below, is a study of the gamma and density curves of a test strip developed with Hibiscus tea, as well as the evolution of tests with “Té del Indio.” Compared to a standard cinematographic laboratory curve, these test results demonstrate strikingly similar tonal ranges and density. Hibiscus tea results do demonstrate a greater chemical fog, which is evident in the lower region of the curve.

Herbal developer density test strip

Herbal developer hibiscus
Herbal developer Hibiscus density chart
Herbal developer Hibiscus developer
Hibiscus developer
Herbal developer Té del Indio Developer
Té del Indio Developer
Herbal developer Arnica Developer
Arnica Developer
Herbal developers General Treegan
General Treegan

Link to videos


This project was generously supported by the chemistry team and developing technicians at the laboratories of Churubusco. It is one of the LEC [Experimental Film Lab, Mexico] and Churubusco Studios and Film Labs residency program 2018.
Residency: LEC-CHURUBUSCO 2018
Resident Filmmaker: General Treegan [born as Andrés Pardo]
General Treegan, born Andrés Pardo, is a film editor, producer, experimental and documentary filmmaker, photo lab nerd and lover of small formats based in Mexico since 2003. He loves black and white, home processing and his Russian camera collection.

14 thoughts on “Herbal developers”

  1. Hi there, I run an analogue photoworkshop at the Art University in Vienna/Austria. We put a focus on “green chemistry” and and we are experimenting with different plant developers. Some films have a very dark haze after the development process. I guess the reason for this may be overdevelopment? Is there a way to remove it? I have heard with citric acid?
    Thanks for sharing!

  2. Hello Mariana,
    No, you can’t just send them down the drain. First, you need to neutralize the solution by adding an acid like citric acid to reach pH 7. Then leave the container for at least a week with no lid where the sun heats it so degradation starts. You will see a color change. When the color change takes place, use the WC so the flush will dilute the solution. If you live in a house that uses a septic tank don’t send it down the drain. You need to build a liquid waste composter.

  3. I’m just starting on my eco-processing journey for still image film, thank you for this information! I’ve been googling and I can’t find information on how to responsibly/safely dispose of the eco-developer after using it a few times. Can you just pour it down the drain?

  4. Leslie, Fog is not related to the plant. Or the solution is too hot or it is too alkaline.
    Any of the formulas in the publication can be used without the plant, just water, once you got it dominated then add the plant.

  5. Your results are impressive! I have been trying the same thing with weeds that grow naturally in my area (nettles, dandelions) but keep getting chemical fogging and lots of white streaks, not sure how to counteract this?

  6. The images of the succulent and the sunflower look great!

    It appears to be working: sodium ascorbate (the developing agent that is a
    reaction product of ascorbic acid and sodium carbonate) used by itself
    is a low-contrast developer (even at low pH). But the two sample images
    have good contrast.

    So either there is some other developing agent at work (perhaps superadditively),
    or you left the film in the developer for a very long time.

    To prove it’s working, you could take two identical shots, then develop one in the
    hibiscus or arnica developer, and the other in the same mixture omitting the
    herbs (as a control case). And include the developing time and temperature
    in the report.

    When one accepts money or donated services for doing research, it’s always good
    to prove scientifically that the product works, and isn’t just “greenwashing”
    (You know: like burning gasoline with hibiscus extract in it in your car as “green fuel”–
    the hibiscus is just along for the ride, so to speak.)

    Rose hips is a natural source of ascorbic acid. But you’d need a lot of them:
    one study found an average of 0.12% and 0.36% by weight depending on biotype,
    with the highest being 1.3%

    One problem with using herbs as sources for a chemical is that the concentration
    of the substance in the raw plant material varies greatly. It is difficult to standardize
    the resulting solution without laboratory testing.

    It would be interesting to get a quantitative analysis to see how much of the tannins–
    if any–are converted to pyrogallol.

    Perhaps the biggest challenge is formulating a stock solution or powder with a good
    shelf life. You may be able to store the herbs in solution in the fridge–but for how long?
    Ascorbic acid powder oxidizes quickly if the container is not air-tight–and slowly even
    if it is.

    You may need to include in the stock solution an oxygen-getter such as sodium sulfite, or
    just massive quantities of ascorbate. If there is another developing agent as the main
    developer and its superadditive with ascorbate won’t increase activity much. It will act
    as an oxygen-getter, protecting the remaining ascorbate and the main developer. So using
    lots of it might be an option for extending shelf life.

    The most sure-fire way to extend shelf-life is to formulate a stock solution that doesn’t
    contain water. But the most solvents commonly used for this purpose, ethylene glycol,
    propylene glycol and TEA (triethanolamine) are not very “green”.

    Developing film is easy; developing film to a desired degree of development with consistent
    results is difficult–especially if you also want a convenient product that can be stored and is
    relatively safe. Arnica is rather toxic, I believe.

  7. Hello. I have a few questions.
    Do you think it’s possible to replenish the arnica developer (adding chemicals after every use to increase usage)?
    Also, would this solution have enough power to develop 120 film, or would I need more than 500ml?

    Thank you!

  8. Lauren, depends on so many things, here where I live is like 28ºC all the year so devs last like 2 weeks, if you are in a cold place will last longer. I freeze the herbal solutions and last months, they lost a little power but still works. After you prepare a developer adding soda and vit C you can bottle with no air and put it in the fridge, that way will last longer. And if you have sodium sulfite you can add 50g per liter and will last like 2 months.

  9. Hi Bob! Yes you still need to fix the negatives, herbal developers works just like any other so you need to fix.

  10. Fascinating and the results are impressive. I have yerba mate and hibiscus blooms in my kitchen for teas – who knew?

Leave a Comment