DRAFT PHOTO POLICY

OCTOBER 2004

To accommodate changes in photographic technology, the National Register
of Historic Places and the National Historic Landmarks Survey have
revised their photograph policy. Effective immediately, a seventy-five
year permanence standard will apply to all photographic prints submitted
as official documentation for National Register and National Historic
Landmark nominations. Any type of black-and-white photographic print
expected to last seventy-five years or longer before showing signs of
fading, discoloration, or other forms of deterioration will be accepted.
This standard approximates the minimum expected longevity of
black-and-white photographs printed on resin-coated (RC) paper, which
the National Register and National Historic Landmarks Survey have
accepted since the early 1980s. Given currently available technology,
two types of prints are acceptable under this policy: 1) black-and-white
photographs printed on fiber-based or RC paper, and; 2) prints made from
digital images that meet the seventy-five year standard. At the present
time, no photographs printed on chromogenic paper meet the seventy-five
year standard, although this may change with future innovations.
Photographs that are improperly processed or incorrectly labeled will be
returned.

This change in policy represents a significant revision of the National
Register and National Historic Landmark (NR-NHL) standards for
photographic documentation. Black-and-white prints have been required
since the inception of both programs because of their superior archival
characteristics. Ensuring the longevity of official documentation,
including photographs, is essential for the administration of federal
historic preservation programs. In addition to the regulatory
protections and grants and tax incentives available under federal law to
properties listed in the National Register or as National Historic
Landmarks, the nomination files for these programs constitute an
irreplaceable archive of American history. When the National Register
and National Historic Landmarks Survey were established, black-and-white
prints were generally made using silver-emulsion fiber-based paper,
which has outstanding archival stability. If stored under proper
conditions, black-and-white prints on fiber-based paper will easily last
150 years or more. In the late 1970s, resin-coated (RC) papers became
popular because of their lower cost and ease of processing. Use of
fiber-based papers consequently became limited to specialized
applications. In response to these changes, the National Register and
National Historic Landmarks Survey began accepting photographs printed
on RC paper in the early 1980s. Thus, as the policy on photographic
documentation evolved over time, it came to be based on two specific
types of commercially produced products, not a minimum requirement for
longevity. The limitations of this policy became clear in recent years
with the advent of digital photography, the introduction of
black-and-white films that can be developed and printed using color
(c-41) processing, and the declining popularity of conventional
black-and-white photography.

The adoption of the seventy-five year permanence standard ensures that
the photo policy will continue to be applicable as manufacturers
introduce new products and discontinue others. This standard provides a
basis for evaluating all currently available photographic materials and
those introduced in the future. Nominating authorities and nomination
preparers are advised that manufacturers' claims sometimes overstate the
expected longevity of products. For this reason, verifiable documentary
information referencing tests conducted by an independent laboratory is
required to demonstrate that a product meets the seventy-five year
permanence standard. This does not mean that nominating authorities will
be expected to contract with independent laboratories to test
photographic materials; rather, readily accessible sources of
information on the permanency of photographs should be used when seeking
authorization from the National Register and National Historic Landmarks
Survey. We recommend that nominating authorities consult the sources
listed at the end of this document in seeking to identify photographic
materials and processing methods that meet the seventy-five year
permanence standard (see "For Further Information"). Other valuable
sources of guidance include curators and archivists who specialize in
photographs at state archives, libraries, and colleges and universities.
In addition, manufacturers sometimes make available results of
independently conducted tests. If credible, this information may be used
to substantiate the longevity of photographs proposed for submission as
official documentation.

Nominating authorities and nomination preparers should also be aware
that the proliferation of so-called "archival" products has made it
difficult to identify products that meet the NR-NHL documentation
standards. No firm definition of archival exists, and many manufacturers
now use the term for marketing purposes. In some instances, products
labeled archival will last considerably longer than non-archival
products but may not meet the NR-NHL standards. Independent testing has
shown that some popular photographic papers marketed as archival, for
example, will begin deteriorating in less than seventy-five years and
therefore cannot be accepted as official documentation. Therefore,
archival products should not be accepted at face value but only if they
meet the NR-NHL documentation standards.

> Because of continual changes in photographic technology, the National
> Register and National Historic Landmarks Survey cannot undertake
> detailed study of new products as they become available. SHPOs, FPOs,
> and TPOs are encouraged to bring new imaging technologies that appear
> to meet the NR-NHL documentation standards to the attention of the
> NR-NHL staff. In cases where nominating authorities wish to submit
> photographs produced with materials and processing methods that have
> not yet been approved, the nominating authority will be required to
> provide information demonstrating that the photographs meet the NR-NHL
> documentation standards. To obtain authorization, a written request
> for approval and any necessary supporting materials (information on
> expected longevity) should be sent to the Keeper of the National
> Register, who also serves as Chief of the National Historic Landmarks
> Survey, for review in advance of submitting any nominations with the
> photographs in question.

Nominating authorities may have additional requirements for
photodocumentation beyond the NR-NHL standards. Nomination preparers and
other interested parties should consult SHPOs, FPOs, and TPOs to ensure
compliance with all applicable standards.

[Digital Photographs]{.underline}

Several options are available for nominating authorities who wish to
submit photographic prints produced from digital images. Consulting a
photo lab in your area that offers professional services is a good
starting point. A number of commercial processing methods produce
high-quality prints from digital images that meet the NR-NHL standards.
If digital services that produce acceptable images at reasonable cost
are locally available, this may prove satisfactory for many nominating
authorities.

Another option is to produce prints in-house with an inkjet or
dye-sublimation photo printer that can use special archival inks and
papers. While most photo printers made for the consumer market are
designed to produce color prints that last only a few years before
fading, a number of manufacturers now offer models which, with the
correct inks and papers, can produce prints with an expected lifespan
comparable to or better than traditional black-and-white prints on RC
paper. These printers can be obtained at reasonable cost, usually under
\$250 with the necessary inks and papers. Producing photographic prints
in-house may result in long-term cost savings and also offers the
important advantage of providing control over the imaging process.

When digitally produced photographs are submitted as official
documentation, they must be accompanied by corresponding electronic
image files. These electronic image files will be used to expedite
online access to NR-NHL documentation, save cost in digitizing
nomination files, and for publications and website features. Electronic
image files submitted as official documentation must be saved as .TIFF
(Tagged Image File Format) files on CD-R media. Uncompressed .TIFF files
are strongly preferred, in keeping with guidance on digital photographic
records issued by the U.S. National Archives and Records Administration.
The size of each image must be 1600x1200 pixels at 300 ppi (pixels per
inch) or larger. It is recommended that digital images be saved in 8-bit
(or larger) color format, which provides maximum detail even when
printed in black-and-white format. The file name for each electronic
image saved on the CD-R must correspond with the photo log included in
the nomination and the information labeled on the back of each
photograph, and it should also reference the county and state in which
the property is located. For example, the image files for the James
Smith House in Jefferson County, Alabama, would be saved as
"Smith1.tiff," "Smith2.tiff," "Smith3.tiff," and so forth.

CD-Rs submitted with a nomination must be labeled with:

-   the name of the property

-   the associated multiple property documentation form (if applicable)

-   and the names of the county and state where the property is located.

[Photographic Technology]{.underline}

The following information about basic types of photographic materials
and processing methods is intended to help nominating authorities and
nomination preparers obtain photographs that meet the NR-NHL standards.
It addresses questions about new products and commonly used terms that
have compounded the difficulty of obtaining acceptable photographs.
While not comprehensive, this guidance provides information for making
informed choices among the vast range of products available in the
photographic marketplace.

The new technologies and photographic materials introduced in recent
years have produced the most dramatic changes in photography since the
advent of color films and printing papers in the 1960s. One consequence
of these changes is the reduced availability of conventional
black-and-white films, papers, and processing. In many cases,
photographic labs capable of producing high-quality black-and-white
photographs can be found only in major metropolitan areas. Declining
demand for traditional black-and-white photography has resulted in
significantly higher costs, which places an added burden on SHPOs, TPOs,
FPOs, and nomination preparers. At the same time, improvements in
digital technology have resulted in the availability of black-and-white
prints that can be obtained at reasonable cost and meet the NR-NHL
documentation standards.

The longevity of a photograph depends on the materials and processing
methods used and the conditions under which it is stored. The NR-NHL
collections are maintained at the National Park Service offices in
Washington, D.C., and are stored under climate-controlled conditions.
Each nomination is placed in an acid-free file folder, with photographs
stored in a separate acid-free sleeve. The conditions under which
nominations are stored are designed for archival longevity. To make
certain that nominations last as long as possible, it is essential that
nomination preparers and nominating authorities submit photographs that
meet the NR-NHL documentation standards.

Photographic film is plastic base coated with a light-sensitive
emulsion. The emulsion is a gelatin in which millions of light-sensitive
silver halide crystals are suspended. Black-and-white film, for example,
has a single emulsion layer that is capable of recording blacks, whites,
and shades of gray. When a camera shutter opens, these crystals in the
film's emulsion layer are exposed to light, causing a reaction to take
place that captures what is called a "latent image." When the film is
removed from the camera and subjected to a chemical developing process,
the light-struck silver halide crystals are affixed to the film and
those that were not exposed to light are removed. The result is a
developed negative that can be used to make photographic prints. To
produce a print, light is passed through a negative and onto
photographic paper, which itself is coated with light-sensitive silver
compounds. The exposure of a negative upon light-sensitive paper
produces a photographic print.

Color-negative film has three emulsion layers that are sensitive to red,
green, and blue light, respectively. In combination, these three
emulsion layers are capable of recording an infinite variety of colors.
Like black-and-white film, the light-sensitive portion of each emulsion
layer is made up of silver halide crystals. Unlike black-and-white film,
however, the crystals in each layer are replaced with colored dyes
during the developing process. The result is a color negative that can
be used to make photographic prints. The process for making color prints
is exactly the same as for black-and-white prints, except that color
paper, which has layers sensitive to red, green, and blue light, must be
used. When light is passed through a color negative and onto color
photographic paper, a color print is produced.

Black-and-white photographic prints have markedly better permanency than
color prints. Most color prints will begin showing signs of
deterioration within only a few years, even if stored under ideal
conditions. Color prints also are subject to uneven fading and color
shifts. For these reasons, the National Register and the National
Historic Landmarks Survey have always required black-and-white
photographs.

Much of the recent confusion faced by nominating authorities and
nomination preparers stems from the introduction of chromogenic
black-and-white films, which share more similarities with color films
than traditional black-and-white films. Chromogenic black-and-white
films, produced by manufacturers such as Kodak and Illford, are
processed and printed using C-41 processing, the method most commonly
used for color photographs. Unlike traditional black-and-white films,
the silver-halide crystals in the emulsion layer of a chromogenic film
are replaced with dyes during the developing process, in the same way
that occurs in processing color film. Chromogenic black-and-white films,
which can be developed at one-hour photo labs and similar facilities,
make it possible for photographers to obtain black-and-white prints
quickly and at low cost. The longevity of these prints, however, tends
to be poor. Because they are produced with color developing and
processing methods and are printed on color paper, they are essentially
color photographs. As a result, they do not meet the NR-NHL standards.

Like conventional photographs, the longevity of prints made with digital
imaging technology depends largely on the materials and ink used.
Initially, the market for digital photographs focused on inexpensive
color prints, which generally had poor longevity. Improvements in
technology and growing demand for digital prints have led manufacturers
to introduce new photo papers, inks, and printing systems, and it is now
possible to obtain photographs made from digital images that equal or
surpass the longevity of conventional black-and-white photographs on RC
paper. Prints made from digital images are available from photo labs
that offer digital services or can be produced using printers and photo
materials available to consumers. Available types of digital printing
papers include versions similar to traditional RC and fiber-based
black-and-white papers. As with conventional photographic materials, the
National Register and National Historic Landmarks Survey recommend that
nominating authorities conduct careful research and check manufacturers'
claims against independent laboratory testing before selecting digital
photo products. Consultation with the NR-NHL staff may also be necessary
in cases where questions exist about the anticipated longevity of
digitally produced prints. It should be remembered that products
marketed as "archival" will not necessarily meet NR-NHL standards for
photo documentation; nomination preparers and nominating authorities
must ensure that photographs made from digital images will last at least
seventy-five years before showing signs of deterioration.

Determining the expected longevity of photographic materials will
continue to be challenging because of ongoing changes in the marketplace
and technological innovation. The information provided above is intended
only as a brief overview of basic photographic technologies. Although
not exhaustive, it is provided to assist nomination preparers and
nominating authorities obtain photographs that meet the NR-NHL
documentation standards.

[For Further Information]{.underline}

The National Register and National Historic Landmarks Survey encourage
nominating authorities and nomination preparers to consult reputable
sources of information in selecting photographs to be submitted as
official documentation. The most current information can usually be
found online. In developing revised standards for photodocumentation,
the National Register and National Historic Landmarks Survey have found
the following websites helpful.

American Institute for Conservation of Historic and Artistic Works:
<http://aic.stanford.edu/>

*Professional membership organization for conservators, including
specialists with photographic materials. A public guide to caring for
photographs is available a:*
<http://aic.stanford.edu/library/online/brochures/photos.html>*. See
also the "Find a Conservator" link for access to an online database of
AIC members, which is a quick and easy way to find a trained photo
conservator in your area.*

Wilhelm Imaging Research:
[www.wilhelm-research.com](http://www.wilhelm-research.com/)

*Henry Wilhelm is widely recognized as a leading authority on the
stability and preservation of traditional and digital photographs. He
conducts research on photo materials and provides consulting services to
museums, archives, and commercial clients. The Wilhelm Imaging Research
website includes data from permanence studies and articles by Wilhelm.
This data is particularly useful when trying to determine if a
particular type of photographic print will meet the National Register
standards.*

Manufacturers' websites provide useful information about
commercially-available products.

Eastman Kodak Company: [www.kodak.com](http://www.kodak.com/)

Fujifilm USA: [www.fujifilm.com](http://www.fujifilm.com/)

The Epson Company:
[www.epson.com/northarmerica.html](http://www.epson.com/northarmerica.html)

RLG DigiNews:
[www.rlg.org/preserv/diginews/](http://www.rlg.org/preserv/diginews/)

*Bimonthly web-based newsletter focusing on digital imaging and
practices in image conservation and digital archiving. Produced by the
Department of Research of Cornell University Libraries for RLG, an
international nonprofit organization of libraries, archives, and
museums.*

California Digital Library Digital Format Standards (2001):
[www.cdlib.org/about/publications/CDLImageStd-2001.pdf](http://www.cdlib.org/about/publications/CDLImageStd-2001.pdf)

*Standards published by the California Digital Library at the University
of California. Provides recommendations for image quality, file formats,
and storage media.*

Columbia University Libraries, Technical Recommendations for Digital
Imaging Projects (1997): [www.columbia.edu](http://www.columbia.edu/)

*Digital imaging recommendations prepared by the Image Quality Working
Group of ArchivesCom, a joint effort of Columbia University Libraries
and Academic Information Systems at Columbia University.*

National Archives and Records Administration Guidance on Digital
Photographic Records:
<http://www.archives.gov/records_management/initiatives/digital_photo_records.html>

*Provides guidance on digital photographic records, including images
captured by digital cameras.*

National Archives and Records Administration Guidance on Scanned Images
of Textual Records:
[www.archives.gov/records_management/initiatives/scanned_textual.html](http://www.archives.gov/records_management/initiatives/scanned_textual.html)

*Although concerned only with scanned images of textual records, this
document includes guidance on digital file formats.*