A Few Words About
Traditional photography relies on the light sensitivity of compounds
based on silver plus chlorine and/or bromine, which make a salt.
Tiny grains of this salt are distributed in gelatin to make an
emulsion. When light strikes the emulsion, the silver compound
chemically. The more light, the bigger the change. A
bath (the developer) reacts with the exposed salt grains, turning them
to metallic silver grains, which are black to the eye. These
grains form the image. The more light and/or development, the
darker the emulsion.
Archival Print Processing
Basically the same process occurs in film and printing paper, only the
substrate is different. Printing paper has a white coating
under the emulsion, to boost the brightness of highlights. Film
is necessarily clear to allow light to shine through when making
prints. Both substrates to carry a thin coating of the
silver-gelatin emulsion. Yes, it's the same gelatin found in
desserts, extracted from bones, but treated to make it much tougher,
physically. For example, an acid bath hardens the gelatin to
After development, the emulsion still contains all the original
grains; some have been converted to black silver, some are still
in the form of the salt. "Fixing" the image dissolves the salt
grains, removing them from the emulsion, so only the developed
grains remain to form the image.
Archival processing addresses all three threats.
- Failure to remove all the undeveloped grains.
Over a long time they may revert to metallic silver, creating unwanted
black areas in the image.
- Failure to remove the fixer, the chemical that
dissolved undeveloped grains. An acid, fixer may corrode the
black silver grains to make them invisible, weakening the image.
- Chemicals in the atmosphere corrode silver grains,
destroying the image.
Toning coats each silver grain with a chemically bonded layer that
resists later chemical activity better than pure silver. Toning
may or may not be visible.
- Thorough fixing ensures full removal of undeveloped grains.
- Additional chemical treatment and washing remove almost all
fixer (a slight trace actually stabilizes the image).
- Toning the image to "armor" the silver grains for
protection from later attack by chemicals.
Selenium is our standard toning material, applied as a "final bath" in
the darkroom process. When used to enhance longevity, selenium
darkens the image slightly, increasing contrast. When left in the
selenium solution for longer times, prints take on a "warm" tone,
shifting from a neutral black. Extended toning changes the color
of the developed grains from black to reddish brown, giving prints an
"antique" appearance that in the past resulted from aging or toning.
To finish its protection, a print is mounted on a stiff board that
resists folding and tearing. The mount also prepares a print for
When framed under glazing , a print must not be placed directly
against the glass or acrylic. To separate the print from the
grazing, a mat board is placed on top of the mount, with a window cut
our to reveal the print.
For full archival treatment, mounts, mats, the adhesive that holds the
print to the mount, and the frames must all be free of acid. Wood
frames are lined with a separator to prevent anthing in the wood from
migrating through the mount to the print.
If our prints don't last 100 years, we'll make another one for
A medium format black and
white negative (2.25 inches square or slightly larger) contains
as much information as a 90 megapixel digital image. Large format
negatives exceed 200 MP.
This high resolution allows prints
larger than 16x20 inches to appear sharp even when examined from close
film, on a base of polyester, lasts as long as prints. That's
for making prints later--no worry about a digital storage medium
growing obsolete and unreadable.