View Full Version : Cyanotype Chemistry

Doug K
01-21-2011, 12:33 PM
I've been using Ware's cyanotype for my first prints. I want to try out the traditional chemistry as well, and upon reading up on it I noticed that a lot of people do 2 parts "A" solution to 1 part "B". So why not double the concentration of the "A" solution?

Also, when using Ware's, I've been adding some citric acid to the solution as per the Photographer's Formulary kit. It seems to make it yellower, and I like the results better than without. It seems like I get a more consistent coating.

What tricks and variations do you use?

01-21-2011, 12:50 PM
Mike Ware's instructions are very clear and precise. His chemistry yields a sensitizer that gives a longer tonal scale than the traditional recipe, which will print a negative with more contrast. It is also much more sensitive to variations in paper chemistry. I find his formula to be much fussier, but usually worth the extra effort. Many papers need to be acidified before Mike's formula will work, and citric acid is always good in the sensitizer, and in the first wash. I mix my own solution from scratch (which makes this process inexpensive), but it requires a little more sophistication than the traditional recipe (heating and filtration are required).

To answer your question about the concentration of the traditional formula, the concentration of the A solution may be close enough to saturation that it would not be possible to double the concentration. The traditional formula is probably the most forgiving of all the alt process formulas. You can use many different variations, and it will work. It also works on just about any substrate. I find that my results with equal parts A and B work as well as anything. The tonal scale will be shorter, so more negatives will work well (they don't have to be as contrasty). The chemicals for the traditional formula are cheap, and the mixing is easy - you don't have to buy a kit or do any tricky chemistry to mix it up - just weigh and stir. Here again, a little citric acid in the sensitizer (when it is mixed for coating) and acidified first wash are also beneficial. Some people use vinegar for the first wash with good results. I wouldn't mess with different concentrations of the A to B ratio until you have made a lot of prints with the 1:1. If you want it darker, then coat twice before you expose. The best part is that you can make a ton of cyanotypes for very little money.

Doug K
02-19-2011, 06:19 PM
Recently I started developing with an acidic initial bath. First I tried just plain white vinegar diluted about 1 to 4. Today I made a bath of 2% Citric acid, and the results are really great. Seems to give a broader tonal range, and a lot more shadow detail. Mike Ware at his website recommends a nitric acid bath, which I will try soon. I've found a local supplier of chemicals, and I'm going to need some dichromate soon, so I'll get some nitric acid while I'm at it.

Anyhow, what I do is an initial soak of a few minutes in the acid bath, then on to plain water which gets changed a couple of times. Going forward I'll be using my Paterson print washer as a final wash.

04-24-2013, 01:24 AM
In my experience the A and B concentrations in the traditional cyanotype can easily vary by 25% or more of either A or B and your results will be just fine and you will likely have a hard time distinguishing between the prints. It's like the Chile or chicken soup of alt process, whatever you throw in, you can get something good out of it and it is very forgiving. I hope I have not offended the souffle folks out there.