Cyanotype Toning formulas

I’ve been working with cyanotype toning baths awhile now, and while I haven’t figured out which ones work best or which one(s) I prefer, I have some basic approaches I’ve locked down.


For the most part, I prefer the effects you get when you first bleach back the print, either for a short while (just until the shadows go from blue to purple, 30-60s) or for a long time (until the image fades to a pale brown/yellow and only the deepest shadows remain a faint gray/blue). Toning without bleaching is very slow and as a result the paper/highlights stain more than I’d like.

Light bleaching results in much of the blue remaining in place, so that the toning happens over it. Heavy bleaching replaces the blue with another color. It can be disconcerting to watch the image fade away, but it’s equally thrilling to watch it come back—often very quickly—once it hits the toning bath.

So far I’ve only tested sodium carbonate bleaching, I still need to test whether ammonia or other alkali work better/differently.

Bleach concentrations:

Type Reagent g / liter timing
Short Na2CO3 1 30-60s
Long Na2CO3 4 5-7m

Toning baths:

Toner tbs / liter color staining notes
Instant Coffee (Nescafe) 8 navy/slate/gray none Dissolved in 180F water, remaining water added to cool
Green Tea (sencha) 4 blue/violet mild Steeped in 180F water for 10m, remaining water added to cool
Black Tea (English breakfast) 4 Dark blue/violet heavy Steeped in 180F water for 10m, remaining water added to cool
Wine Tannin (home-brew grade) 2 eggplant black mild Dissolved in 180F water, aged overnight

Some preliminary color notes:


Timings vary, but my current MO (working with prints that have been dried and aged at least overnight) is:

Another method I have tested is this one (found here):

Some possibly useful web links about cyanotype toning:

February 7, 2019 · cyanotype · cheat sheet · photography · toning

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