Cyanotype whites not clearing

I'm using Mike Ware's cyanotype formula and mixed it per his instructions. I am omitting the dichromate from the formula.

I've been careful to mix the solution under an incandescent bug light to prevent fogging of the solution and I'm using distilled water.


My solution is emerald green in the bottle and my coated paper is a strong yellow-green color. This is at odds with Mike Ware's description of lemon yellow when coated on the paper.


If I coat the paper then attempt to clear it immediately upon drying with no exposure to blue or UV light, I still get some blue in the paper that does not completely clear out.

I've gotten this result with Arches Aquarelle cold press, Hahnemühle Platinum Rag, and Legion Revere Platinum. The Arches Aquarelle is the worst of the three. I've added a drop of 40% citric acid per milliliter of solution per Christina Anderson's Cyanotype book. This does not seem to yield any change.

What could I be doing wrong here?

cirwin2010 said:

Mike Ware's cyanotype formul

Click to expand...

New Cyanotype or Simple? I guess the former. It's very picky with regard to the paper you use and I find it takes a dilute mineral acid to clear it. I use very dilute hydrochloric/ muriatic acid. You may have to neutralize any carbonate buffer in the paper if the whites don't clear.
Overall, the plain old classic cyanotype formula is the most dependable and easiest to use.

cirwin2010 said:

I'm using Mike Ware's cyanotype formula and mixed it per his instructions. I am omitting the dichromate from the formula.

I've been careful to mix the solution under an incandescent bug light to prevent fogging of the solution and I'm using distilled water.


My solution is emerald green in the bottle and my coated paper is a strong yellow-green color. This is at odds with Mike Ware's description of lemon yellow when coated on the paper.


If I coat the paper then attempt to clear it immediately upon drying with no exposure to blue or UV light, I still get some blue in the paper that does not completely clear out.

I've gotten this result with Arches Aquarelle cold press, Hahnemühle Platinum Rag, and Legion Revere Platinum. The Arches Aquarelle is the worst of the three. I've added a drop of 40% citric acid per milliliter of solution per Christina Anderson's Cyanotype book. This does not seem to yield any change.

What could I be doing wrong here?

Click to expand...

From look of the things, that does not bode well for the sensitizer. Somehow it might have been compromised while you were making it. I don't know if you want to mess with this or make a new batch. Potentially if there was any ferrous formed in the sensitizer, it can be reverted by addition of hydrogen peroxide.

:Niranjan.

koraks said:

New Cyanotype or Simple? I guess the former. It's very picky with regard to the paper you use and I find it takes a dilute mineral acid to clear it. I use very dilute hydrochloric/ muriatic acid. You may have to neutralize any carbonate buffer in the paper if the whites don't clear.
Overall, the plain old classic cyanotype formula is the most dependable and easiest to use.

Click to expand...

New cyanotype per Mike Ware's instructions. I have yet to try a sulfamic acid presoak with the papers or increasing the amount of citric acid added to the sensitizer.

nmp said:

From look of the things, that does not bode well for the sensitizer. Somehow it might have been compromised while you were making it. I don't know if you want to mess with this or make a new batch. Potentially if there was any ferrous formed in the sensitizer, it can be reverted by addition of hydrogen peroxide.

:Niranjan.

Click to expand...

So the new cyanotype sensitizer isn't supposed to be this green? I've watched Bill Schwab's video on youtube (link below) and I think I've mixed my solutions the same way, but with perhaps a bit more heat and precision? The way he heats the solution seems a bit loose.


This is actually my second batch I've made. I thought the same thing, thinking I messed something up since I used tap water and some brighter led lights to illuminate my work space. The second bath I used distilled water and mixed the solutions under an incandescent bug light to ensure it wasn't tap water contamination or my lights exposing the solution. From my testing both the first and second batch appear to be the same.

I'm not really sure how I can mix it any better than I have. I'm using clean beakers and a hot plate. My thermometer is probably not the most suitable, but I figured it should be close enough. At lease closer than how Bill Schwab was doing it.

Still assuming that something is going wrong if even HPR is fogging a little bit.

Try making just 2 ml of fresh half-strength sensitiser without any heating:

Ammonium Iron(III) Oxalate (NH4)3[Fe(C2O4)3].3H2O	0.3 g
Potassium Ferricyanide K3[Fe(CN)6]	0.1 g
Distilled water to make	2 ml

Coat some paper strips and check if they still turn green.

I've used this instant sensitiser with cheap papers (after neutralising the buffer) and it works fine. Produces slightly less intense blue as noted by Mike Ware. YMMV.

I ended up using something like Raghu posted ( add a little bit of citric acid or FAC if you get ferric potassium oxalate crystals on the surface of your print ). One thing I noticed about "new" cyanotype was that mine had a little bit of fine prussian blue suspended in it. It caused something like you are noticing on your HPR and RP. Just a guess is that your Aquarelle is not compatible, and that the other two might have a little of this "staining" prussian blue suspended in the solution. I was able to filter it out, but then I got annoyed when more appeared a few days later and now the bottle is still on the shelf!

Dichromate is supposed to prevent the formation of Prussian Blue in seasoned sensitiser. However, for instant use, I've not had the need to use Dichromate nor have I seen any Potassium Ferric Oxalate crystals on the coated paper when half strength sensitiser is employed. I don't mind the extra effort that instant brewing demands as a small volume user.

cirwin2010 said:

New cyanotype per Mike Ware's instructions. I have yet to try a sulfamic acid presoak with the papers or increasing the amount of citric acid added to the sensitizer.

Click to expand...

Okay, see how that goes. Don't forget what I said about the rinse after exposure. Citric acid etc. is not sufficient for this in my experience. Try dilute hydrochloric acid.

I don't know what your sensitizer looks like, but what I see mostly is what might be a healthy sensitizer applied to a paper that's just not suitable (without neutralization) for this process.

I'd strongly suggest setting New Cyanotype aside as it's just unnecessarily fussy and problematic. That's just my private opinion though.