Toning Cyanotypes with Matcha

You either hate it or you love it. But Matcha isn't just for drinking!

Why Matcha Can Tone Cyanotype

Matcha’s rich chlorophyll content makes it an excellent toning agent. Matcha is made from green tea leaves, grown under shade for about three weeks before harvest. This shading process increases chlorophyll levels.​  Chlorophyll is responsible for the green pigment in plants and plays a crucial role in photosynthesis. Matcha Toning Cyanotype. At this point my question was: would it produce a similar result to green tea toning? Well, no. And I can prove it. High-quality matcha has a bright green color, indicative of its high chlorophyll content, and works best for toning. Lower quality matcha, with its duller, brownish-green color, is less technically effective. Now, Matcha is expensive and while the cheaper one has a lower chlorophyll content let me tell you, it works just as well!

What Happens When You Tone Cyanotype

When you tone a cyanotype print, a chemical reaction occurs between the iron compounds in the print and the toning agent. In a standard cyanotype, ferric ammonium citrate and potassium ferricyanide react to form Prussian blue (ferric ferrocyanide). Toning agents, such as tea or tannins, interact with the iron compounds, altering their chemical structure and thus changing the color of the print. This process often replaces some of the iron in the Prussian blue with other metal compounds, resulting in a variety of hues, from sepia to green or blue-black, depending on the toning material used.

How to do it

• Preparation: Add 1 to 2 teaspoons of matcha powder to 70 to 100 ml of water heated to 70°C to 85°C (158°F to 185°F). Let it sit to develop a rich green solution.
  

• Bleaching: Submerge the cyanotype print in a sodium carbonate solution for about 15 minutes to lighten the image.
  

• Toning: Place the bleached print in the prepared matcha bath. Allow it to tone for 2-3 hours. The longer the print remains in the bath, the more pronounced the color change.

Cyanotype print, bleached, then toned with matcha

A comparison:

Same digital negative, emulsion and bleach.

Rooibos Tea: Moderate contrast, with a smooth gradient between the light and dark areas, gentle depth. Warm tonality, soft sepia, antique look with orange-brown undertone.

Green Tea: The contrast is slightly higher than the Rooibos Tea print, offering more definition especially around the facial features. Cooler, more neutral tones, greenish-grey undertone.​​​ Matcha: The contrast in the Matcha print is the most pronounced among the three, with deep shadows and well-defined highlights. Rich, deep color and saturation, very vibrant with a pinky undertone.

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