Most people associate cyanotype with its characteristic blue colour. Contrary to popular belief, however, cyanotype does not have to remain blue — there are many ways to tone the finished print and change its colour.
One particularly interesting option is a black-to-aubergine cyanotype toner, which can shift the colour of the print towards deep black with violet and aubergine tones.
Preparing the Print for Toning
A cyanotype intended for this type of toning should be overexposed, approximately twice as much as usual.
After exposure, the print should be washed thoroughly, dried and allowed to oxidise naturally for at least 24 hours.
Before toning, soak the print again in clean water.
Bleaching the Cyanotype
The first stage is bleaching the print in the bleaching solution.
The degree of bleaching affects the way the toner will act later and therefore has a significant influence on the final colour.
For a subtle effect, immerse the print in the bleaching solution only briefly and then transfer it to clean water. This can be repeated until the desired degree of bleaching is achieved.
After bleaching, wash the print thoroughly in running water for approximately 10–15 minutes.
Toning the Print
Transfer the washed print to the toning solution and leave it there until the desired colour is reached.
Excessively long toning may stain the paper base. This can reduce contrast and make the brightest areas of the print appear less clean.
Once toning is complete, wash the photograph thoroughly again for approximately 15 minutes.
The bleaching solution can also be used independently to lighten overexposed cyanotype prints.
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| Partially bleached cyanotype before black-to-aubergine toning. |
Experimenting with the Process
When toning cyanotypes, it is worth experimenting and occasionally breaking the usual rules.
For example, you can try toning prints immediately after washing, without allowing them to oxidise for 24 hours, or compare different degrees of bleaching before toning.
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In every case, however, the print should be washed thoroughly between the individual stages and again at the end of the process.
Residual processing chemicals can affect both the appearance and the long-term stability of the finished photograph.