I hope to:
a. encourage others to try this process, for the results
can be quite lovely
b. learn more from replys by workers with more
experience & insight
Exposure:
Carbon exposure is a contact-printing method. Sandwich the prepared,
sensitized, dry carbon "tissue" with the negative using two sheets of
plate glass or a contact printing frame. Expose using a UV-rich light
source. I'm using a 175-watt mercury-vapor lamp (an old city
streetlight unit) mounted about 13 inches above the printing surface.
Exposure is "about" ten minutes. Your times may vary.
Preparing the Final-Support paper for transfer:
Before the printing session, fix (no hardner) and wash a matt-surface
photographic paper (I'm using Ilford Multigrade Fiber *Matt*) and dry
it.
While the exposure is being made, soak the Final Support paper in
120-140 degree F distilled water for 5 minutes. Move the Final Support
paper from the hot soak to a tray of room-temp (68 F) distilled water
for 5 minutes. (Total soak = 10 minutes)
After the exposure, place the soaked Final Support paper and the
exposed tissue side-by side in a tray of distilled water (68 F) .
Remove any bubbles gently with a wetted soft brush.
As soon as the exposed tissue lies reasonably flat, place the dark
(emulsion) side of the tissue face down on the emulsion side of the
Final Support paper. Pull the pair carefully from the water to avoid
bubbles.
Place the joined paper sandwich on a clean sheet of glass, with the
sensitized tissue emulsion facing down and the Final Support paper
facing up. Working in 4 directions from the center, squeegee the papers
together. Gradually pressing harder until the squeegee begins to drag.
After squeegeeing, place the two-paper "sandwich" between 4-6 layers
of newsprint or newspaper. Place this assembly of papers between two
sheets of glass and place a weight such as a filled gallon jug on top to
give pressure. Let this set for 15 minutes (68 F)
Place the tissue/FS paper sandwich in a tray of distilled water at
105 degrees F. Agitate gently. After about 1 minute, dark
carbon/gelatin will begin to ooze out around the tissue edges. Holding
them underwater, VERY gently begin to pull the tissue/FS paper sandwich
apart.
When the papers are separated, remove the tissue and continue to
agitate the Final Support paper to remove the excess gelatin emulsion.
5 minutes or more may be needed to clear the image.
Transfer the FS paper to cool distilled water (68 F) to harden the
gelatin image.
Clear any potassium dichromate stain from the image by placing the
print in a tray of 5% Sodium Metabisulfite (68 F) for 5 minutes or so.
Wash by changing the water bath multiple times.
Hang to dry (or pin the paper down to a sheet of cardboard to minimize
curling.
Enjoy!
As I indicated in my "Carbon Tissue 101" post, please contact me to
ask questions, rant-'n-rave or whatever. I've tried to make these posts
as brief as practical, while including the needed info.
Good light,
Bill Clark
wmclark@prairieweb.com
Scottsbluff Nebraska USA