Weblog Entry - 04/16/2004: "book lust"

It won't be published for about another year or so, but the forthcoming Encyclopedia of Nineteenth-Century Photography will be a "must have" for anyone with an interest in the history and development of photography.

I'm both excited and a little scared. Excited because you know how I am about historical methods and techniques. I doubt I'll get through it in one sitting but there's a good chance it will become bedtime reading, with an entry or two per night. And scared because the amount of potential projects and things to learn about already on my to do list is enough to keep me busy for some time. Can you imagine the state I'll be in with a list of entries as long as my arm?

Photogeek babble on Dektol bleaching and tannic acid toning of cyanotypes follows...

While leafing through Christopher James' book, I came across some tips on toning cyanotype prints. While the natural deep blue of a cyanotype is appealling in its own way, the first few toning methods seemed simple enough to carry out that a quick investigation was in order.

I'd already played the household ammonia/strong tea game and wasn't particularly thrilled by the sort of purplish tones it gave the print. Just a bit too soft and delicate for my taste.

The next method, with it's mention of "smoky black" tones, sounded much more interesting. After printing a few cyanotypes to use as test pieces, I bleached them back to a golden yellow in a solution of dilute Dektol (1:3) developer. The bleaching took place quite quickly although I was able to stop it just before the last hint of blue faded away.

After a good wash, several times longer than the suggested few minutes, the wet print was lowered into a tray with a 3% tannic acid solution. The tannic acid solution was prepared the night before, well in advance to allow the stubborn material to completely dissolve in water. Within a few minutes the light yellow had become a nice dark grey and a short time later the shadows began to take on a dark tone that approached the look of shadows in a selenium toned silver gelatin print.

A thorough wash followed, a good 30 minutes in running water, and then the prints were set aside to dry. They are still a bit too damp for scanning and there may be some more color changes ahead as they dry completely. After an hour and a half of drying they have reached an unusual but not unpleasant red/purple/brown tone. It's similar to a Van Dyke in some ways but has a hint of maroon that I rather like.

Except for the mixing time of the tannic acid solution, the toning process was quick, painless and gave quite acceptable results. Unlike my previous tea experiments, the paper base remained a clear bright white, with no hint of staining or yellowing. The rich reddish brown is every bit as powerful as the deep blues of the original print. One more trick to add to the toy chest.