The Pigment Processes - Photographic Processes Series - Chapter 8 of 12

0:07One of the major themes in photography is this desire to have a more permanent image. You have the woodburytype. You have the platinum print. Very stable, very long lasting processes. Then you also have the pigment family of processes. The gum bichromate process and the carbon print process.

0:48The gum print is based on the light sensitivity of chromium. Mungo Ponton is the first person to really do experiments with the light sensitivity of this compound. Talbot himself experiments with chromium salts. He discovers that if you mix them with colloids gelatin or gum they harden when they are exposed to sunlight.

1:11Based on the work of Talbot it doesn’t take too much time for people to figure out that if we take a colloid like gum arabic, and we put pigment into those, and then sensitize those with chromium salts we now have a medium that can brushed onto paper expose it to light under a negative and when we put this paper in warm water areas that are struck by light will harden, and that’s where the dark pigment will be.

1:41Areas that are not struck by light will dissolve away, leaving the white of the paper. So now we have a brand new printing process, based on chromium. If you look at a gum print, the darker the picture, the thicker the deposit of gum. The whiter the picture, the more you are getting towards the actual paper.

2:02So the image itself will have slight relief. One of the names associated with gum printing and carbon printing is Alphonse Poitevin. He is a Frenchman who perfects certain elements of chromium printing. While it is still imperfect, it is the seed to an improvement that is later done by Joseph Swan that results in the process we now call carbon printing.

2:30It is essentially a piece of paper that is coated with gelatin that is bearing pigment. This thing is called the “tissue” but it is not tissue like at all, it’s like a piece of plastic. The tissue is sensitized with chromium. It is then contacted printed with a negative.

2:51The light striking the gelatin hardens it selectively. The tissue is then put into cold water, and a second piece of paper bearing clear gelatin on the surface is put into contact with the tissue. They are slid into a tray with hot water. The unhardened gelatin with pigment oozes out the edges.

3:16It is softening because of the hot water. You peal off the original tissue, and by washing it in hot water you take away all the black you don’t need in order to get a continuous tone photograph. The image you get is very very permanent. It is still being done today, there are still people making carbon prints today.

3:41Pictorialists really established photography as a fine art form. They used things like the gum bichromate process or platinum prints that involved a lot of hand work and craftmanship. You really had a sense of the photographic object as something that was made by somebody.

4:03Alfred Stieglitz is the person most associated with what was called the photo-secession. He and Edward Steichen co-founded the movement. They promoted this idea through a publication called Camera Work. Stieglitz had a gallery called 291 in New York that showed photography as an artform.

4:29This was a camera that was used by Alfred Stieglitz. It was given to the museum by Georgia O’Keeffe in the 1950’s. The opening of that lens determines the sharpness of the picture. If you open it up quite a ways, you get an image that is soft around the edges.

4:45He was interested in pictorialist photography, and this was the lens designed to do that. Stieglitz, Steichen, and Kasebier wanted people to take photography seriously as a fine art form. Not just an automatic activity that produced images without anybody’s intervention.

5:05I think what the argument was really about was where is the creative input of the artist in photography. That is a theme that goes back to the invention of the medium.