How to preserve Chlorophyll prints

Bárbara Morais shares her process of preserving – otherwise unstable – Chlorophyll photographs, making them UV resistant.

Writer and photography / Bárbara Morais

Preserving Chlorphyll photographs from UV light

“Nature is the final place where memory lies.”

Binh Danh.

Mr. Binh Danh, the photographer who has made famous the chlorophyll prints, said that this is a whole process of attempts and errors, in which “only one in every five prints is successful”.

To make it even more “precious”, who makes chlorophyll prints knows the anguish of seeing the degradation of the image when exposed to the sun, aggravated with the fragility of the leaf itself. These facts give rise to the general idea of chlorophyll prints as a temporary photographic process, fragile, unstable – vulnerable to time.

But, can we do something to preserve chlorophyll prints? Binh Danh preserves them in two- or three-inch-thick blocks of resin. What kind of resin? I can’t find any information. So, I decided to look for techniques of preservation of leaves in the area of botany and culinary.

The technique that I present to you is the way I preserve my chlorophyll prints. I have little experience, yet. My leaves only have 4 weeks of existence, but they’re perfect!

How (and why) to do

Chlorophyll, the large molecule with a long tail and a body holding Magnesium atom at its center, gives vegetables the green color. High temperature, acidic medium, and exposure of the chlorophyll molecule to the cell’s own enzyme will result in the loss of the Magnesium atom or the tail, a prime reason for losing the green color.

The principle involved in this technique is to bring about a combination of the chlorophyll in the cells of the plant with copper. The resulting compound, copper phyllocyanate, is practically insoluble and isn’t destroyed by light. So, we need Copper Sulphate.

In slightly acidic medium, hydrogen atoms replace the magnesium atom of the chlorophyll pigment. One way to avoid losing the ‘bright green’ is to soaking leaves in a slightly alkaline water adding a pinch of baking soda since the amount of hydrogen atoms required to displace the magnesium is less. There is one drawback – adding excess of baking soda can turn the vegetable mushy.

Glycerin is used to preserve leaves without pressing, giving them a more natural appearance, soft and supple.

We will also need 95% alcohol, formalin.
Chemicals for preserving prints

1The most difficult part of the process is to get the copper into the cells before the chlorophyll escapes or breaks down. In order to accomplish this, the air of the tissues must be removed, by immersion in 90 to 95 percent alcohol for 20 minutes and then soaking for some time in boiled water (whit a pinch of baking soda for 4 liters of water) after the latter has cooled.

Chlorophyll bath
the leaves must be placed in a dilute 5% glycerol solution

2Then, the leaves must be placed in a dilute 5% glycerol solution containing enough dissolved copper sulfate to give it a marked bluish tint. The solution should be boiled before using to free it from air.
At the time of using, enough formalin should be added to make the solution about 1%. The leaves should be left in this until all of the green parts have assumed a bluish-green color.

The leaves should be left in this until all of the green parts have assumed a bluish green color.

3They should then be removed to a dilute glycerin-formalin solution free from copper. This will gradually dissolve all the copper not in combination whit chlorophyll and thus bring out the natural shade and variations.
After thorough washing and clearing in this latter solution the material may be preserved, without change, in any of the common media except strong alcohol.

bring out the natural shade and variations

4At the end, I paint the sheet with UV-resistant varnish, so as to be able to expose the leaf to the sun running at less risk of damaging the image.

paint the sheet with UV-resistant varnish
And this is my chlorophyll print
And this is my chlorophyll print, placed in a frame made of acrylic, which allows the visualization of the leave in all its dimensions!
Chlorophyll print

Most relevant sites found

Bárbara Morais is a physician, living in the North of Portugal. A self-taught photographer is a lover of alternative photographic processes. She exhibited her photographs at the Order of Physicians-Oporto and won the first prize of photography of the Portuguese Association of General Clinic Physicians in 2015.

Did you learn something?
We would like YOU to become a Supporting Member to help us keep this learning resource free and accessible to all.
An article takes 1-4 days to write, edit and publish. The research behind the article takes between one day and a lifetime. No one gets paid for this and your contributions and membership are crucial to help with running costs.
Apart from supporting our free learning and inspirational resource, you are also eligible to take part in our members-only events, all for the price of a coffee once a month.
Other ways to support us are buying our books, calendars and journals directly from us, or using our affiliate links to buy books which gives us a tiny percentage. You can also get a t-shirt, card or apron from our Etsy store earning us a small commission.
We really appreciate your support and THANK YOU to the heroes who already support us!

6 thoughts on “How to preserve Chlorophyll prints”

  1. Hi – I was researching this and came across your article. I am wondering how your chlorophyll prints are holding up with this method.

  2. This is really interesting. Please could I ask, where do you purchase the required products? I am actually also in Portugal and I hope to preserve the colour of seaweed

  3. Have you tried this with plant matter prints (anthotypes) on more traditional substrates such as paper? All of these concerns are what are going through my head as I make these prints that I basically can’t show in sunlight because it is the sun that bleaches and crates the positive image.

  4. Thank you for the excellent article. I have been working for years to solve the same problem. I have not had a lot of luck with coper sulfate, but my process is very different. I create images with algae, on a permanent substrate. For my work, I use oven blanching. I believe the ultimate answer may be in the the use of a lightfast skin, that stains the image but not the background. So far, i have not had any success in this approach, but there are so many stains to try. I have set up a fading test using sunlight to get a simple relative test to compare the efficacy of different techniques on the reduction of fading. I still don’t have the answer, and may never have it, but it is fun to try. Keep up the good work, and thanks again for your ideas.

Leave a Comment