I spent this sunny Sunday making some new cyanotypes, some of which I plan to hand-tone with tannic acid from black tea. Keep in mind, this is a chemical process, not digital or Photoshop toning.
The process starts with watercolor paper sensitized with the cyanotype solution, a large negative that’s the actual size of the final contact print, and some sunlight. This is one of the oldest (and easiest) processes in the history photography, and results in a beautiful shade of blue instead of blacks in the shadow areas.
The problem with cyanotypes is that everything is blue
While cyanotypes are striking and beautiful, not everyone likes blue prints. And it’s true, a blue landscape is a little odd. So, there are ways to chemically change the color of the blue. Today I experimented with toning with black tea.
Here’s how the toning process works
Because cyanotypes are a type of contact print, you need a negative that’s the same size as your final print size. Large negatives can come from large format cameras, or they can be made digitally in Photoshop from a digital photograph, and printed onto transparency film with a high-quality inkjet printer. A third option is the one I’m currently using, which is to output digital files onto photographic film with an LVT machine.
I made a series of prints from different negatives for various lengths of time, as the sun passed over head. I tracked the lengths of exposure and time of day on each print. Many photographers who regularly make alternative prints use a well-controlled electric UV light source, but for me, it’s the changing sunshine.
Bleaching and toning
Once the cyanotypes have aged, they can be soaked in a bath of water and laundry washing soda, which bleaches away most or all of the blue, leaving the paper almost pure white.
The bleached print can then be rinsed in water, and transferred to soak in a bath of strong tea, coffee, even red wine — anything with tannins. The tannic acid in the tea bath replaces the original cyanotype iron salts and stains the paper, giving it an aged look, and returning the bleached image in the color of the tannins.
The final print is rinsed in fresh water to get as much of the tea out of the paper as possible, then dried and ready to frame.
Step by Step Guide
- Select or make the negative
- Mix chemistry and sensitize the watercolor paper (pre-sensitized cyanotype paper is affordable and widely available). This can be done in semi-dim conditions or under indirect room light as long as it’s not UV light or bright daylight.
- Sandwich negative and paper into an exposure frame (this can be two sheets of glass clamped together
- Expose to UV light (sunlight or an electric UV light source)
- Rinse the exposed print under tap water to develop it
- Allow the print to fully dry and age to full richness
- To remove the blue, soak the print in water, then quickly soak in a bleach bath made from water and laundry washing soda (not laundry detergent washing powder). This happens very quickly.
- Rinse under tap water to remove the washing soda bath
- Soak in the toning bath of tea, coffee, or red wine
- Rinse and allow to dry