Toned Cyanotype

I have been wanting to try this for a while and this weekend I finally had some time to read up and give it a go. I had bought some wine tannin a while back since tannin is the primary component in tea that is responsible for toning cyanotypes. With the powdered tannin I can skip the brewing step and be a little more quantitative/reproducible about the process. So what did I do?

The image I used was from a while back. It is a 4x5 negative on x-ray film. For details of that image, look here. The cyanotype sensitizer I used was the traditional formula (not the Ware formula) and I have to admit it has been sitting in my photo box for probably a year or more. That is a testimony to the longevity of those solutions and the archival quality of the prints. The paper is Arches 90# hot press watercolor paper (love that stuff). The exposure was 6 minutes (probably should have done 8) in the waning autumnal sun (5:00pm in San Diego). The first bath was about 1:4 white vinegar:tap water. That was intended to extend the tonal range and I think it worked pretty well. Look at the bellows on the camera and you can see quite a few grays in there. Also, the blacks are 'just black' and not too blocky. This might be lost on the computer monitor, but the print is quite nice. The highlights are blown because I under-exposed the print, but that can be remedied next time. Then I washed in lots of plain water until the highlights cleared and were the same color as the borders of the paper. I then did another quick bath in dilute hydrogen peroxide to fully develop the iron. This can be done by drying the print and just waiting a few days, but I am impatient. Another plain water wash and it was time to tone.

I mixed ½ tsp washing soda in 500mL of distilled water.
I mixed 1 tsp wine tannin in 500mL of distilled water.

Starting with the soda bath, I alternated soda... water... tannin... water... for about 30 sec each until it started looking the way and the color I thought I wanted. Here is what I ended up with.