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| Image from Graphic Atlas |
Key Elements
- Popular during 1885 to 1910 [1]
- First manufactured in Germany in 1885 as a collodion
silver chloride paper[3]
- Part of the larger family of photographic papers that were printed out compared to being developed in a chemical bath[3]
- Collodion refers to a "viscous fluid obtained when
pyroxylin (cellulose nitrate) is dissolved in a mixture of alcohol and
ether"
- stems from the wet collodion process discovered by Frederick Scott Archer, which used collodion as a binder for silver salts in photographic prints[4]
- experiments using collodion as the carrier for silver
salts in making paper prints started around 1861
- In 1867, hand-coated collodion printing-out paper was
commercially available
- Images were created entirely by exposure to light as it
was with albumen and salted papers
- To create collodion printed-out papers, photographers
used sensitized emulsions coated on barytapaper in continuous rolls
- the paper contained a sensitized emulsion of silver
chloride stabilized by the presence of citric acid
- In printing-out papers, collodion is the transparent
layer in which the light sensitive silver salts were suspended
- It is the image carrying layer also known as the
binder
- These emulsion papers have a shelf life 1 year under
favorable conditions
- Has three layers
- A paper support
- A baryta layer
- A collodion layer
- Manufactured with a glossy and matte surfaces
- Glossy collodion printing-out papers have a thicker baryta layer with smooth
continuous surface and a thicker collodion layer
- The baryta layer gives the paper support its smooth, white
surface
- Used gold toning as a finishing for the processing of
images produce on this printing-out paper
- Images tend to have a reddish-brown to purple tone due to gold toning[2]
Inventors and Important Photographers
·
Collodion POPs does not have a clear
inventor
o
Combination of various inventions
made throughout the 19th century
·
Several inventors and photographers
associated with the invention of this type of photographic process and other
collodion photographic processes include:
o
Marc Gaudin in 1853 introduced
collodion emulsion
o
William Henry Fox Talbot possibly
introduced collodion on paper in 1854
o
G.W. Simpson in 1865 introduced
collodion photographs
o
J.B. Obernetter developed commercial
collodion chloride paper in 1867
Uses of Collodion POPs
·
Used for portraits of both
groups and individuals[2]
·
Used as an alternative to albumen
photographs by both amateur and professional photographers
·
Most of them were produced as
cabinet cards[1]
·
Used for smaller prints and card
photographs of various formats
·
Amateur photographs found this
process easier to work with
o
ability to use their smaller cameras
o
work with commercially made silver
glass plate negatives
o
reduce the steps spent processing
the image in the dark room[2]
Identification
·
When identifying this process look
for warm image hues/tones
·
Using a microscope look for
invisible paper fibers
·
Under a microscope the binder
(collodion) and the baryta layers should be present
·
The paper fibers should also be at
least partially if not completely obscured in highlights
·
Iridescence is also a way to
identify this process
o
Caused by the collodion emulsion
o
Move the print around and watch the
reflection of light off the print’s surface
o
Fluorescent light works best
o
A majority of collodion POPs exhibit
iridescence[1]
·
Difficult to distinguish glossy
collodion printing-out papers from gelatin printing-out papers
·
When dating prints that use this
type of photographic process, consider the context clues of the image such as
clothing and hair styles used in the images
o
Remember that this process was
popular during the time of portraits
o
The popularity of this photographic
process was late 1880s to early 1920s and most prints will be from this period
of time
o
Production of this type of print
ended in the 1930s, so it will be rare to find a print from after this time[2]
Preservation Concerns
·
In dealing with the preservation of
prints made from this process, there are several deterioration concerns to
consider
·
Collodion POPs deteriorate mainly
due to structural problems, abrasion of the collodion layer, and changes in the
photolytic silver image
·
Have a tendency to curl due to
exposure to moisture
o
The collodion layers do not absorb
moisture and swell
o
Difficult to work with
o
Most prints will be mounted on a
solid matte board due to this problem
·
The
collodion layer is not very flexible, as a result can cause hairline cracks and
fractures
·
Should store these prints in protective
envelopes[3]
·
Since the collodion layer is so
thin, abrasion is a serious problem
o
White scratches across the surface
due to penetrating through to the white baryta layer
o
Gouges and dull spots
·
Due to oxidative reductive
deterioration, prints with gold toning experience loss of highlight detail, a
shift in image color, and fading[4]
·
Sulfiding deterioration will also
cause fading of highlights and blackening of the image as well as fading of the
image to a yellowish or greenish-brown
·
As a result of frequent handling,
mechanical damage can occur[2]
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| Image from Graphic Atlas |
[1] “Collodion POPs,” Graphic Atlas, accessed September 21,
2015, http://www.graphicsatlas.org/identification/?process_id=40.
[2] Art Kaplan, and Dusan C. Stulik,
“Collodion on Paper,” in The Atlas of
Analytical Signatures of Photographic Processes (Los Angeles: The Getty
Institute Conservation Institute, 2013),
http://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/atlas_collodion.pdf
[3] Bertrand Lavedrine, Photographs of the Past: Process and
Preservation (Los Angeles: The Getty Conservation Institute, 2009).
[4] James M. Reilly, Care and Identification of 19th Century
Photographic Prints (Rochester, NY: Eastman Kodak Company, 2009).
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