PMG Photographic Processes

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Page Information
Date initiated: January 2010
Contributors: Amy Brost, Luisa Casella, Tatiana Cole, Kim R. DuBoise, Lisa Duncan, Monique Fischer, Saori Kawasumi Lewis, Amanda Maloney, Alejandra Mendoza, Laura Wahl, Stephanie Watkins


The Importance of Photographic Process Identification[edit | edit source]

Many photographic materials look similar, yet the chemistry behind them varies greatly. "Without detailed knowledge and understanding of the photographic processes used in making a given photograph, it is extremely difficult to determine the environmental conditions needed for the photograph’s long-term preservation, as well as the maximum light levels that should not be exceeded during display or exhibition. A detailed knowledge of the process chemistry, the processing and post-processing treatment, and the potential deterioration pathways is also needed when developing conservation and preservation treatments". [1].

"The identification of photographs and photographic processes based solely on visual and microscopic inspection of photographs can be used to answer more than 75% of identification questions successfully". [1].

Process Identification methodologies[edit | edit source]

Graphics Atlas[edit | edit source]

The Graphics Atlas from Image Permanence Institute presents a Photographic Process Identification Methodology and Controlled Vocabulary that analyzes the key identifying features of each photographic process. By observing and identifying the characteristics of each photograph, the unique combination of features leads you to a correct identification.

These key identifying features in this methodology are divided into three groups:

1. Object View

  • Primary Support
  • Image: Color/Tone, Quality
  • Formats/Mounting
  • Finishing Techniques
  • Deterioration Characteristics
  • Information Written or Printed on Object


2. Surface View

  • Surface Sheen
  • Surface Texture
  • Deterioration Characteristics


3. Magnification

  • Image Structure
  • Layer Structure
  • Deterioration Characteristics


The Atlas of Analytical Signatures of Photographic Processes[edit | edit source]

The Atlas of Analytical Signatures of Photographic Processesby Dusan Stulik and Art Kaplan is intended for professionals that may need to identify more unusual photographs and that may have access to analytical techniques to study them. It provides identification information in terms of:

1. Visual Signatures

  • Visual Characteristics
  • Microscopic Characteristics


2. Analytical Signatures

  • XRF
  • FTIR
  • Other Analytical Signatures relevant to each process


CAMEO of the Museum of Fine Arts, Boston, contains information and representative images of various photographic materials, including a short reference list. Gawain Weaver compiled a useful controlled vocabulary of photographic processes that includes a list of synonyms and specific products associated with photographic processes.

Photographic Processes[edit | edit source]

The list of photographic processes below is modeled after Bertrand Lavédrine's organizational structure, with permission.
The pages linked below aim to offer a baseline knowledge of photographic processes from a Photograph Conservator's perspective, and list links particularly relevant for the preservation and conservation of those materials.

Positives on Metal See also Cased Photographs[edit | edit source]

Heliograph[edit | edit source]

Daguerreotype [edit | edit source]

Tintype[edit | edit source]

Positives on Glass See also Preservation of Glass in Photographic Materials[edit | edit source]

Ambrotype: Positive Collodion See also Cased Photographs[edit | edit source]

Color Screen Processes[edit | edit source]

Lantern Slides[edit | edit source]

Opalines, Opaltypes, Opalotypes[edit | edit source]

Positives on Plastic[edit | edit source]

Dye Diffusion Processes[edit | edit source]

Holograms[edit | edit source]

Positives on Paper[edit | edit source]

Albumen[edit | edit source]

Lightly Albumenized Salt Print[edit | edit source]

Bromoil, Oil-Pigment[edit | edit source]

Carbon[edit | edit source]

Carbro, Ozotype, Anthrakotype, Ozobrome[edit | edit source]

Chrystotype[edit | edit source]

Cyanotype, Blueprint, Pellet Print, Argyrotype[edit | edit source]

Collodion-Chloride Paper[edit | edit source]

Gum Bi/Dichromate[edit | edit source]

Platinum, Palladium[edit | edit source]

Silver Gelatin Printing-Out, Silver Gelatin Developing-Out, Resin Coated (RC), Photostat[edit | edit source]

VanDyke Brown, Kallitype, Brown Print, Sepia Print, Ferro-Gallic, Argentotype, Agyrotype[edit | edit source]

Mechanically Printed Positives on Paper[edit | edit source]

Collotype[edit | edit source]

Letterpress/Half-tone[edit | edit source]

Photogravure (etching)[edit | edit source]

Woodburytype See also Carbon[edit | edit source]

Mechanically Printed Positives on Paper or Plastic[edit | edit source]

Computer-generated digital-sourced print See also Digital Prints[edit | edit source]

Negatives on Paper[edit | edit source]

Albumen Negatives[edit | edit source]

Salted Paper Negatives[edit | edit source]

Photogenic Drawings, Salted Paper Prints, and Calotype Prints[edit | edit source]

Negatives on Glass See also Preservation of Glass in Photographic Materials[edit | edit source]

Collodion Negative See also Cased Photographs[edit | edit source]

Gelatin Dry-plate Negative[edit | edit source]

Lantern Slides[edit | edit source]

Negatives on Plastic Film[edit | edit source]

Color negatives on plastic support See also Preservation of Traditional Color Photographic Materials[edit | edit source]

Black and white negatives on plastic support[edit | edit source]

Mechanically Printed Negatives on Paper or Plastic[edit | edit source]

Computer-generated digital-sourced print See also Digital Prints[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 Stulik, Dusan C. and Art Kaplan. 2013. The Atlas of Analytical Signatures of Photographic Processes. Los Angeles: The Getty Conservation Institute.


Resources[edit | edit source]

AIC Learning: Photographic Chemistry for Preservation

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