LE GRAY’S WAXED-PAPER NEGATIVE PROCESS
From Conservation of photographic negatives
| Survey of Negative Processes | Paper-Based Processes |
Contents |
[edit] historical background
- published 1851 by Gustave Le Gray
- paper was waxed before sensitization
- could be stored longer than calotype paper
- no moist exposure necessary but possible
(COE, BRIAN, 1986, p 29)
- less sensitive than calotype, although fast displacement of all other negative paper
(NADEAU, LUIS, 2006, p 117)
- especially popular in GB and France, less in the USA
(COE, BRIAN; HAWORTH-BOOTH, MARK, 1983, p 28)
[edit] process
- Wax fills the paper not completely, so chemicals still can permeate
- prewaxed negatives are more stable in water based solutions, therefore much thinner paper can be used.
(DAFFNER, LEE ANN, 2005)
[edit] preparation
- solution of potassium iodide, bromide (restrainer: too fast blackening with iodide alone, protects paper white from gallic acid) and sodium chloride in isinglass (alternatively: collodion in alcohol: more sensitive)
(GRAY, GUSTAVE le, 1850)
- waxing before sensitization (different additional binding media like whey, albumen, isinglass, rice water)
(DAFFNER, LEE ANN, 1995)
- heating of a daguerreotype plate (copper plate)
- melting of wax on it
- pressing the back of the negative against it
- after impregnation taking the negative off and ironing between some layers of paper (taking off excessive wax)
(GRAY, GUSTAVE le, 1850)
[edit] sensitization
(GRAY, GUSTAVE le, 1850)
- silver nitrate + water + acidic acid
- floating of the paper on the solution for 1 to 5 minutes (several repetitions): all salts have to be converted
- back must stay dry
[edit] exposure
(GRAY, GUSTAVE le, 1850)
- wet paper on a glass frame of a camera, sensitized paper on top of it
- package stays moist for approximately 1 hour (prolonging by gum arabic coating on first wet paper layer or glass plate sandwich)
- exposure time: 2 seconds to 2 minutes
[edit] development
(GRAY, GUSTAVE le, 1850)
- Development within 1 hour
- gallic acid spread on a glass plate
- paper pressed against it, development can be seen through the back
- development time: 10 to 30 minutes (fastening by heating up the gallic acid)
- bluish grey fog shows over exposure
[edit] fixing
(GRAY, GUSTAVE le, 1850)
- sodium thiosulfate for 30 to 45 minutes
- also potassium bromide stabilization possible
[edit] washing
(GRAY, GUSTAVE le, 1850)
- changing water bathes
- subsequent bath in fresh water for 45 minutes
[edit] variations
- TURPENTINE WAXED NEGATIVE by Maurice Lespiault, chemicals merged with a mixture of wax and solvents before applying it fluidly to the paper (similar to Tillard’s turpentine and wax process?)
( DAFFNER, LEE ANN, 1995; NADEAU, LUIS, 2006, p 148)
- collodion as binding media by Stephane Geoffroy
(DAFFNER, LEE ANN, 1995)
- gelatin as binding media by Edouard Baldus
(DAFFNER, LEE ANN, 1995)
- different binding media like albumen
(DAFFNER, LEE ANN, 1995)
[edit] References
- COE, BRIAN, 1986. Das erste Jahrhundert der Photographie 1800-1900. Bindlach: Gondrom
- COE, BRIAN; HAWORTH-BOOTH, MARK, 1983. A Guide to Early Photographic Processes. London: Victoria and Albert Museum
- DAFFNER, LEE ANN, 1995. Examination and Investigation of the 19th Century Paper Negatives. A Study of the Process, Materials and Deterioration Characteristics. Topics in Photographic Preservation, 6, 1-10
- DAFFNER, LEE ANN, 2005. Coatings on Paper Negatives. In: Constance McCabe ed. Coatings on Photographs. Washington D.C.: AIC. 66-77
- GRAY, GUSTAVE le, 1850. A Practical Treatise on Photography upon Paper and Glass (translated by Thomas Cousins, London). In: Doug Munson. Workshop in Photograph Conservation, Selected Readings, Silver Print-Out Media, January 6-10, 1997, 13-26
- NADEAU, LUIS, 2006. Encyclopedia of Printing, Photographic and Photomechanical Processes (1st eBook ed., V.1.1.). Fredericton, NB (Canada)
