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A while back I experimented with Mike Wares "Simple Cyanotype" using concentrated ammonium hydroxide. I miked a solution somewhere between his low and medium density range formulas, going for a required density range about 2.0 to make it compatible with my VanDyke Brown printing negatives I've experimented with. For VanDykes, I use a formula from Sandy King that uses citric acid instead of tartaric, in fact that formula uses half as much citric acid as ferric ammonium citrate. This is also about the optimal DR for the new Ferroblen printing process for those following that.
As it turn out the Simple Cyanotype wasn't very simple. It was difficult to mix. I combined the FAC with the Potassium Ferricyanide, but it kept for ony a few weeks in the refrigerator. The sensitizer itself was not optimum for 2.0 density, but for closer to 1.5, and most of the blue dissolved out in the water like traditional cyanotype unlike the less soluble FAC I thought I had made. My ammonium hydroxide was supposed to be 28% but I had no way to confirm that.
Then I got the brite idea to mimic my Sandy King formula for VanDyke and use half as much citric acid as FAC with classic cyanotype. My thinking was that the VanDyke, which is a cyanotype developed with silver nitrate instead of potas. ferri. Since it's optimum for 2.0 dr, the classic cyanotype may be as well with the same amount. The simple cyanotype makes the sensitizer more or less acidic to control contrast. So I mixed a 20%-10%-10% sensitizer (fac-citricac-pferr) and coated some cheap watercolor paper. It much greener than normal, so I was worried it had gone bad with the paper. However it printed just fine, and was a fair match to my 2.0 density range negatives. Also, very little of the blue washed out, just as I expected with simple cyanotype. This allows much longer washing times than classic cyanotype without removing pigment. It also has better tonality than classic.
So this is a way to lower the contrast of classic cyanotypes and is much simpler. Ten percent is about the limit of how much citric acid can be added to a 20-10 (FAC-PF) due to solubilities, but less will give more contrast. It works the same way as Mike Ware's simple but has less of a range. I mix my sensitizer just enough for one sheet at a time. This also gives contrast control over a shorter range but still a useful one. Citric acid is more available, cheaper, and more stable than concentrated ammonia solutions.
Try it, you'll like it.
As it turn out the Simple Cyanotype wasn't very simple. It was difficult to mix. I combined the FAC with the Potassium Ferricyanide, but it kept for ony a few weeks in the refrigerator. The sensitizer itself was not optimum for 2.0 density, but for closer to 1.5, and most of the blue dissolved out in the water like traditional cyanotype unlike the less soluble FAC I thought I had made. My ammonium hydroxide was supposed to be 28% but I had no way to confirm that.
Then I got the brite idea to mimic my Sandy King formula for VanDyke and use half as much citric acid as FAC with classic cyanotype. My thinking was that the VanDyke, which is a cyanotype developed with silver nitrate instead of potas. ferri. Since it's optimum for 2.0 dr, the classic cyanotype may be as well with the same amount. The simple cyanotype makes the sensitizer more or less acidic to control contrast. So I mixed a 20%-10%-10% sensitizer (fac-citricac-pferr) and coated some cheap watercolor paper. It much greener than normal, so I was worried it had gone bad with the paper. However it printed just fine, and was a fair match to my 2.0 density range negatives. Also, very little of the blue washed out, just as I expected with simple cyanotype. This allows much longer washing times than classic cyanotype without removing pigment. It also has better tonality than classic.
So this is a way to lower the contrast of classic cyanotypes and is much simpler. Ten percent is about the limit of how much citric acid can be added to a 20-10 (FAC-PF) due to solubilities, but less will give more contrast. It works the same way as Mike Ware's simple but has less of a range. I mix my sensitizer just enough for one sheet at a time. This also gives contrast control over a shorter range but still a useful one. Citric acid is more available, cheaper, and more stable than concentrated ammonia solutions.
Try it, you'll like it.
