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Carbon Transfer Print I recently tried a new (for me) photographic process. This process is an old process dating to 1855. This process carbon transfer printing is one in which a camera negative is created in camera using film. In my case, I photograph with a 5"X 7" field camera. I use a film manufactured in Croatia and develop the exposed negative in Pyrogallol developer. I use the same formula that Edward Weston used in developing his film. The Pyrogallol developer provides great acutance with proportional staining based upon the silver halide density of the negative. The proportional staining is important because carbon tissue is the broadest density scale of any photographic process. This staining allows expanding the density range of the negative to take advantage of the wide density carbon printing provides. The image produced in carbon transfer printing is contact printed on colored gelatin tissue. Thus the final image becomes the size of the camera negative. This is a departure from silver or platinum prints which are either contact printed or enlarged. The tissue is made by using 250 bloom gelatin and lamp black or pigmented water colors. Thus an image can be any color that one chooses for the tissue. The tissue is sensitized with ammonium dichromate. Upon exposure to ultra violet light the dichromate becomes ammonium chromate. The tissue is exposed in direct proportion to the range of density of the camera negative. I expose to sunlight with a typical exposure being in the 2-5 minute range. After the tissue is exposed, the next step is to mate the tissue to the final support paper. The final support paper is gelatin coated and the tissue and support are mated emulsion to emulsion in 75 degree water. Once mated the tissue and support are pressed and held under pressure for one hour. After the one hour pressurized mate is completed the tissue and support are developed in water at 104 degrees until the tissue begins to disperse after which the tissue is removed from the support and the image is now transferred to the support and is fully developed in the same water. The unexposed tissue disperses in the developer water and the exposed image remains on the support. Why would anyone go to all of this trouble to make a carbon transfer print? There are several reasons. The first is this is the most archival process available to a photographer. The image is limited to the life of the paper. If one uses acid free cotton (rag) paper the life of the image will be hundreds of years. The image will not fade. The second reason is that a carbon transfer print when observed exhibits a three dimensionality because the carbon tissue that remains to form the image varies in thickness in proportion to the density of the image. The image that is attached is one of the carbon transfer prints that I have completed.  |
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Awesome Don- Love This Thank you! "The only way to have a friend is to be one."
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Interesting technique and effect ~ it would be interesting playing with different images, layering as well perhaps?
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