Cyanotype printing and botanical toning: A comprehensive guide for photography enthusiasts

Cyanotype printing is one of the oldest and most accessible alternative photographic printing processes. Recognised for its deep Prussian blue tones and handcrafted workflow, cyanotype combines photography, chemistry, paper, ultraviolet light, and experimentation into a highly tactile image-making process.

Botanical toning extends the process further by transforming the original blueprint into earthy browns, muted greys, sepia tones, and textured surfaces using natural ingredients such as coffee, tea, pomegranate peel, clove, and green tea.

This guide explains how cyanotype works, how botanical toning affects the print, the materials required, common mistakes beginners make, and the practical lessons that improve consistency and print quality.

What is cyanotype printing?

Cyanotype is a photographic printing process invented by Sir John Herschel in 1842. The process uses two iron-based chemicals:

• Ferric Ammonium Citrate

• Potassium Ferricyanide

When mixed and coated onto paper, the solution becomes sensitive to ultraviolet light. Once exposed and washed, the image develops into a rich blue monochrome print commonly known as Prussian Blue.

Unlike silver gelatin printing, cyanotype does not require a darkroom enlarger. Exposure can be done using sunlight or artificial UV lights, making it one of the simplest entry points into alternative photographic printing. Must read : My experience of working with cyanotype prints for the first time

Materials required for cyanotype printing

A basic cyanotype setup includes: Chemicals

• Ferric Ammonium Citrate

• Potassium Ferricyanide
  

Paper

Popular choices include:

• Hahnemühle Photo Rag

• Fabriano Artistico Hot Press

• Cold-pressed watercolour papers
  

Coating brushes

The coating brush affects chemistry distribution and print texture significantly. Commonly used brushes include:

• Japanese Hake Brush

• Brustro Artists Hake Flat Watercolour Brush

Japanese Hake brushes generally produce softer and more even coatings, especially on smooth papers. Brustro Hake brushes may create slightly more visible brush textures, which can work well for handmade-looking prints.

Additional tools

• UV exposure light or sunlight

• Digital negative or film negative

• Washing trays

• Gloves and measuring tools

• Stouffer step wedge for exposure testing

How cyanotype printing works

The cyanotype process typically follows these steps:

1. Mix equal parts of Ferric Ammonium Citrate and Potassium Ferricyanide

2. Coat the solution evenly onto the paper

3. Allow the paper to dry completely in darkness

4. Place a digital negative or film negative over the coated paper

5. Expose under UV light or sunlight

6. Wash the print thoroughly in water

7. Allow oxidation and drying to complete the final blue tone
   

Even small variations in coating thickness, humidity, exposure time, or washing technique can dramatically alter the result.

Understanding exposure and UV light

Exposure is one of the most important variables in cyanotype printing. Different UV light sources produce different results even at identical exposure times. Factors influencing exposure include:

• UV intensity

• Distance from light source

• Paper absorbency

• Negative density

• Humidity

• Coating consistency
  

A Stouffer step wedge is highly useful for evaluating exposure accuracy and tonal separation. It helps determine:

• highlight retention

• shadow blocking

• optimal exposure timing
  

Proper exposure testing significantly improves print consistency.

Choosing the right paper

Paper choice changes the final appearance of the cyanotype dramatically.

Hot-pressed papers

• smoother texture

• sharper detail

• cleaner tonal transitions

Cold-pressed papers

• rougher surface

• increased texture

• more organic absorption patterns
  

Different papers also react differently during toning and washing. There is no universally “best” paper; the ideal choice depends on the image style and desired final texture.

Common mistakes in cyanotype printing

1. Uneven coating

Rushed coating often produces streaks, blotches, or inconsistent density.

Solution:

• coat slowly and evenly

• maintain consistent brush pressure

• avoid overloading the brush
  

2. Incorrect drying

Exposing damp paper causes muddy or inconsistent results.

Solution:

• ensure complete drying before exposure
  

3. Poor exposure timing

Underexposure produces weak prints; overexposure blocks highlights.

Solution:

• test exposure systematically

• use step wedges whenever possible
  

4. Water chemistry issues

Hard or alkaline water can shift cyanotype tones unexpectedly.

Solution:

• test filtered or distilled water for consistency
  

5. Incorrect chemistry ratios

Imbalanced chemical mixtures affect tonal depth and print stability.

Solution:

• maintain equal-part chemical mixing carefully

What is botanical toning?

Botanical toning is the process of altering cyanotype colours using natural ingredients. The toner interacts with the iron compounds within the print, shifting the original blue into different tonal ranges.

Botanical toning can affect:

• colour

• tonal depth

• contrast

• texture

• emotional atmosphere of the image
  

The process often produces:

• warm browns

• sepias

• muted greys

• purple tones

• textured surfaces
  

How botanical toning is done in cyanotype printing

Botanical toning is usually done after the cyanotype print has been fully exposed, washed, oxidised, and dried. The process alters the original Prussian blue colour by allowing natural ingredients to react with the iron compounds present in the print.

Although every toner behaves differently, the general workflow remains similar.

Also read: My experience working with botanical cyanotype prints

Step-by-step botanical toning process

1. Create a fully processed cyanotype print

Before toning begins, the cyanotype print should be:

• properly exposed

• thoroughly washed

• completely oxidised

• fully dry

Toning unstable or partially washed prints often produces muddy or inconsistent results.

2. Prepare the botanical toner solution

Different ingredients require different preparation methods.

Common botanical toners include:

• coffee

• tea

• green tea

• clove

• fenugreek

• pomegranate peel
  

The ingredient is usually:

• boiled in water

• steeped for a longer duration

• filtered thoroughly before use
  

Filtering is extremely important because undissolved particles may stain or damage the print surface unintentionally.It works particularly well for:

• portraits

• heritage photography

• architecture

• landscapes
  

Because tannic acid does not dissolve completely, the solution usually requires repeated filtering through mesh cloth or coffee filters. Interestingly, slight irregularities from remaining particles often enhance the handmade appearance of the print.

For ingredients such as pomegranate peel, repeated filtering using:

• mesh cloth

• coffee filters

may be necessary because tannic acid particles often remain suspended in the liquid.

3. Bleaching the cyanotype print (optional but recommended)

Many botanical toning methods work better when the cyanotype print is lightly bleached before toning. A mild bleaching solution is commonly prepared using:

• washing soda (sodium carbonate) or

• ammonia-based diluted solutions

The print is immersed briefly until the blue begins fading into pale yellow or grey.

Important:

Over-bleaching can permanently damage the image and reduce tonal depth. The print should be removed immediately once the highlights begin shifting.

4. Washing after bleaching

After bleaching:

• Wash the print thoroughly in clean water

• remove all remaining bleaching chemicals

Residual bleach can interfere with the botanical toner and create uneven staining.

5. Immersing the print in the botanical toner

The bleached cyanotype print is then immersed into the prepared botanical solution.

During this stage:

• the image gradually shifts colour

• tones deepen slowly

• texture and density begin changing

Different toners react at different speeds.

Typical observations:

• Coffee turns out to be warm, earthy browns

• Tea turns out to be sepia-like tones

• Green tea turns out to be muted greys or purple shifts

• Clove turns out to be a darker shadow depth

• Pomegranate peel turns out to be rich-textured browns
  

Toning duration may vary from:

• a few minutes to

• several hours

depending on the desired result.

6. Observing the colour transformation

Botanical toning is highly dependent on observation. The final colour is influenced by:

• paper type

• water chemistry

• toner strength

• exposure quality

• humidity

• chemistry ratios

At this stage, two identical cyanotype prints may tone differently. This unpredictability is a natural part of alternative printing.

7. Final washing and drying

Once the desired tone is achieved:

• Wash the print thoroughly again

• allow it to dry naturally

As the print dries and oxidises further, the colour may continue shifting slightly over time. Many-toned cyanotypes appear lighter while wet and deepen after drying.

Important lessons while botanical toning

Water quality matters

Hard or alkaline water can dramatically alter colour outcomes, especially when acidic ingredients like lemon-based green tea are used.

Paper changes the result

Hot-pressed and cold-pressed papers absorb toners differently and influence texture significantly.

Filtering matters

Improperly filtered botanical ingredients may create:

• unwanted stains

• excessive grain

• inconsistent surfaces

However, controlled irregularities sometimes enhance the handmade appearance of the print.

Every toner behaves differently No botanical toner reacts the same way.

Even the same toner can produce different results depending on:

• chemistry balance

• humidity

• paper absorbency

• coating consistency

• exposure timing

Why botanical toning is valued in alternative printing

Botanical toning transforms cyanotype from a purely blue printing process into a highly experimental and expressive medium.

The process allows photographers to:

• create unique colour palettes

• introduce organic textures

• produce vintage tonal qualities

• create completely unrepeatable prints

Because every print reacts differently, botanical toning often produces results that feel handcrafted, tactile, and deeply individual.

Why is botanical toning unpredictable

Botanical toning depends on multiple variables simultaneously:

• paper type

• water chemistry

• humidity

• toner acidity

• coating consistency

• exposure quality

• chemical ratios

• drying conditions

Even with identical exposure settings, two prints may tone differently. This unpredictability is a natural part of alternative printing and often leads to unique, unrepeatable results.

Why cyanotype teaches patience

Cyanotype printing is a slow process compared to digital workflows.

The process involves:

• coating

• drying

• exposing

• washing

• oxidising

• toning

• drying again
  

Each stage requires attention and timing. The slower pace helps photographers understand how chemistry, light, paper, and process interact physically rather than digitally.

In summary

Cyanotype printing and botanical toning combine photography, chemistry, craftsmanship, and experimentation into a highly rewarding alternative printing process. From selecting papers and brushes to controlling UV exposure and experimenting with botanical toners, every stage influences the final image differently.

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