Print permanence

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Print permanence refers to the longevity of printed material, especially photographs, and preservation issues. Over time, the optical density, color balance, lustre, and other qualities of a print will degrade. The rate at which deterioration occurs depends primarily on two main factors: the print itself, that is, the colorants used to form the image and the medium on which image resides, and the type of environment the print is exposed to.

Contents

Inkjet prints

For inkjet prints, pigment-based inks last generally longest when used with specific paper types, whereas dye-based inks can be optimal on more types of paper. Ink-jet paper types include swellable paper, porous paper, and cotton rag paper.[ citation needed ]

Chromogenic color prints (silver halide prints)

The longevity of images on chromogenic color photographic papers depends on the temperature and relative humidity of the storage environment, and on the total light exposure they receive. Older chromogenic papers undergo more rapid fading compared to modern materials. For example, Fujifilm's Crystal Archive papers have a quoted longevity of sixty years dark storage. [1] The stability of coupler-incorporated chromogenic prints has steadily increased since their introduction by Kodak in 1942. Very significant advances in stability were made in case of Kodak prints in 1954, 1958, and in the early 1980s. These changes can often be used for the dating of color prints, and can be correlated with manufacturing changes documented in the technical literature. [2]

Monochrome prints

In general, black-and-white prints using either silver or carbon-based media may last longer than some colour prints. Some black-and-white prints are produced using ink-jet printers, or colour photographic paper using the RA 4 process.

Gelatin silver prints

To achieve a long lifespan, gelatin silver prints must be thoroughly fixed and washed. Besides rendering the image insensitive to further light exposure, fixer converts undeveloped silver salts in the emulsion into products that can easily be washed away. Effective fixing and washing removes all unexposed silver salts and leaves only a small amount of residual fixer. Any significant quantity of fixer (thiosulphate) left in the print after washing will cause the image to deteriorate over time. Many other factors play a critical role in the long-term stability of gelatin silver prints. The temperature and relative humidity of the storage environment, and the air pollutants to which a silver image is exposed are three of the most important factors. [3]

Toning can increase the longevity of silver-based prints by replacing or coating the metallic silver with more inert metals such as gold, silver sulphide or selenium. [4]

Platinum, palladium and other inert metals

Images composed of more inert metals, like platinum, palladium and gold are less prone to decay than those in silver. Amateur Photographer's Dictionary of Photography said "Owing to the chemically inert nature of platinum, a print so made is far more permanent than any print having a silver image can be". [5] Indeed, the Victoria and Albert Museum's Conservation Journal states that "...the majority of the deterioration seen in such prints is usually associated with the supports, which are often yellowed and brittle, rather than the actual image." [6]

Environmental factors

Environmental factors that hasten the deterioration of a print include exposure to heat, ozone and other pollutants, water or humidity, and high levels of light. Though light-induced fade often gets the most publicity, greater than 90 per cent of consumer prints are stored in the dark where the effects of heat, humidity, and/or pollutants can dominate.

Research and standards

Much research into image permanence has been carried out by Wilhelm Imaging Research, Inc. [7]

Some film companies and printer manufacturers are researching ways to increase the lifetime of their prints. The International Organization for Standardization has developed standards for keeping photographs, defined in ISO 18920. Those standards have yet to be extended to digital print output, though the organization has signaled its intent to provide such standards.

See also

Related Research Articles

Photographic processing or photographic development is the chemical means by which photographic film or paper is treated after photographic exposure to produce a negative or positive image. Photographic processing transforms the latent image into a visible image, makes this permanent and renders it insensitive to light.

<span class="mw-page-title-main">Photographic paper</span> Light-sensitive paper used to make photographic prints

Photographic paper is a paper coated with a light-sensitive chemical formula, like photographic film, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then developed to form a visible image; with most papers the image density from exposure can be sufficient to not require further development, aside from fixing and clearing, though latent exposure is also usually present. The light-sensitive layer of the paper is called the emulsion. The most common chemistry was based on silver halide but other alternatives have also been used.

<span class="mw-page-title-main">Gelatin silver process</span> Photographic process

The gelatin silver process is the most commonly used chemical process in black-and-white photography, and is the fundamental chemical process for modern analog color photography. As such, films and printing papers available for analog photography rarely rely on any other chemical process to record an image. A suspension of silver salts in gelatin is coated onto a support such as glass, flexible plastic or film, baryta paper, or resin-coated paper. These light-sensitive materials are stable under normal keeping conditions and are able to be exposed and processed even many years after their manufacture. The "dry plate" gelatin process was an improvement on the collodion wet-plate process dominant from the 1850s–1880s, which had to be exposed and developed immediately after coating.

Photographic printing is the process of producing a final image on paper for viewing, using chemically sensitized paper. The paper is exposed to a photographic negative, a positive transparency , or a digital image file projected using an enlarger or digital exposure unit such as a LightJet or Minilab printer. Alternatively, the negative or transparency may be placed atop the paper and directly exposed, creating a contact print. Digital photographs are commonly printed on plain paper, for example by a color printer, but this is not considered "photographic printing".

C-41 is a chromogenic color print film developing process introduced by Kodak in 1972, superseding the C-22 process. C-41, also known as CN-16 by Fuji, CNK-4 by Konica, and AP-70 by AGFA, is the most popular film process in use, with most, if not all photofinishing labs devoting at least one machine to this development process.

<span class="mw-page-title-main">Platinum print</span>

Platinum prints, also called platinotypes, are photographic prints made by a monochrome printing process involving platinum.

The science of photography is the use of chemistry and physics in all aspects of photography. This applies to the camera, its lenses, physical operation of the camera, electronic camera internals, and the process of developing film in order to take and develop pictures properly.

<span class="mw-page-title-main">Carbon print</span> Photographic printing process

A carbon print is a photographic print with an image consisting of pigmented gelatin, rather than of silver or other metallic particles suspended in a uniform layer of gelatin, as in typical black-and-white prints, or of chromogenic dyes, as in typical photographic color prints.

Ilfochrome is a dye destruction positive-to-positive photographic process used for the reproduction of film transparencies on photographic paper. The prints are made on a dimensionally stable polyester base as opposed to traditional paper base. Since it uses 13 layers of azo dyes sealed in a polyester base, the print will not fade, discolour, or deteriorate for an extended time. Accelerated aging tests conducted by Henry Wilhelm rated the process as producing prints which, framed under glass, would last for 29 years before color shifts could be detected. Characteristics of Ilfochrome prints are image clarity, color purity, and being an archival process able to produce critical accuracy to the original transparency.

Kodak Ultima is a brand of photo paper for inkjet printers sold by Eastman Kodak.

LightJet is a brand of hardware used for photographic printing of digital images to photographic paper and film. LightJet printers are no longer manufactured but are however remanufactured and resold; and their lasers are still manufactured.parts and service still available.

The conservation and restoration of photographs is the study of the physical care and treatment of photographic materials. It covers both efforts undertaken by photograph conservators, librarians, archivists, and museum curators who manage photograph collections at a variety of cultural heritage institutions, as well as steps taken to preserve collections of personal and family photographs. It is an umbrella term that includes both preventative preservation activities such as environmental control and conservation techniques that involve treating individual items. Both preservation and conservation require an in-depth understanding of how photographs are made, and the causes and prevention of deterioration. Conservator-restorers use this knowledge to treat photographic materials, stabilizing them from further deterioration, and sometimes restoring them for aesthetic purposes.

Chromogenic photography is photography that works by a chromogen forming a conventional silver image and then replacing it with a dye image. Most films and papers used for color photography today are chromogenic, using three layers, each providing their own subtractive color. Some chromogenic films provide black-and-white negatives, and are processed in standard color developers. In this case, the dyes are a neutral color.

A chromogenic print, also known as a C-print or C-type print, a silver halide print, or a dye coupler print, is a photographic print made from a color negative, transparency or digital image, and developed using a chromogenic process. They are composed of three layers of gelatin, each containing an emulsion of silver halide, which is used as a light-sensitive material, and a different dye coupler of subtractive color which together, when developed, form a full-color image.

<span class="mw-page-title-main">Inkjet paper</span> Paper designed for use with inkjet printers

Inkjet paper is a special fine paper designed for inkjet printers, typically classified by its weight, brightness and smoothness, and sometimes by its opacity.

RA-4 is Kodak's proprietary name for the chemical process most commonly used to make color photographic prints. It is used for both minilab wet silver halide digital printers of the types most common today in photo labs and drug stores, and for prints made with older-type optical enlargers and manual processing.

Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography, it consists of silver halide crystals dispersed in gelatin. The emulsion is usually coated onto a substrate of glass, films, paper, or fabric. The substrate is often flexible and known as a film base.

Art photography print types refers to the process and paper of how the photograph is printed and developed.

The conservation and restoration of film is the physical care and treatment of film-based materials. These include photographic film and motion picture film stock.

<span class="mw-page-title-main">Conservation and restoration of photographic plates</span>

The conservation and restoration of photographic plates is caring for and maintaining photographic plates to preserve their materials and content. It covers the necessary measures that can be taken by conservators, curators, collection managers, and other professionals to conserve the material unique to photographic plate processes. This practice includes understanding the composition and agents of deterioration of photographic plates, as well as the preventive conservation and interventive conservation measures that can be taken to increase their longevity.

References

  1. ↑ Wilhelm, Henry; McCormick-Goodhart, Mark (January 2000), An Overview of the Permanence of Inkjet Prints Compared With Traditional Color Prints (PDF), retrieved 6 September 2008
  2. ↑ Weaver, Gawain; Long, Zach (2009), Chromogenic Characterization: A Study of Kodak Color Prints, 1942-2008 , retrieved 30 October 2009
  3. ↑ Weaver, Gawain (2008). "A Guide to Fiber-base Gelatin Silver Print Condition and Deterioration" (PDF). Retrieved 30 October 2009.
  4. ↑ "Archival processing 2". Archived from the original on 2008-07-23. Retrieved 2008-09-05. | Silverprint article on print longevity | Accessed 5 September 2008
  5. ↑ Sowerby, A.L.M., ed. (1961), Dictionary of Photography - A Reference Book for Amateur and Professional Photographers (nineteenth edition), London: Iliffe Books Ltd., p. 515
  6. ↑ Gent, Megan; Rees, Jacqueline (July 1993). "A Conservation Treatment to Remove Residual Iron from Platinum Prints". Victoria and Albert Museum, London. Retrieved 6 September 2008.
  7. ↑ http://www.wilhelm-research.com/index.html%7C Wilhelm Imaging Research, Inc. website | Accessed 5 September 2008
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