ISO 18918:2000
(Main)Imaging materials — Processed photographic plates — Storage practices
Imaging materials — Processed photographic plates — Storage practices
1.1 This International Standard specifies dark storage conditions, storage facilities, and handling and inspecting procedures for processed photographic plates having integral photographic layers and intended for record purposes. 1.2 This International Standard is applicable to black-and-white, silver-image, gelatin, processed photographic plates as defined in 3.7.7. It is also applicable to medium-term and extended-term storage conditions as defined in 3.6 and 3.2, respectively. No specific distinction is made, other than the degree of care, between photographic plates for medium-term or extended-term storage. Recommendations for plate storage relate to materials, methods, conditions, and forms of protection applicable specifically to plates defined in 1.1. However, these storage recommendations may also be applied to lacquered and opaque plates, to black-and-white plates altered by dyes or toners, colour plates and other historic photographic plates defined in 3.7.2 to 3.7.8. 1.3 It is not intended to predict or assign a useful lifetime to processed photographic plates stored in accordance with the specifications of this International Standard. 1.4 Recommendations for storage of photographic films are given in ISO 18911 and for storage of processed photographic reflection print material in ISO 18920. Although there is some variation in recommended storage conditions among these types of photographic materials, recommended temperature and relative humidity ranges do overlap. If all three types of photographic materials are found in one collection or within one storage area, the temperature and relative humidity should be chosen so that all materials are stored within their recommended ranges.
Matériaux pour image — Plaques photographiques développées — Directives pour l'archivage
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 18918
First edition
2000-03-15
Imaging materials — Processed
photographic plates — Storage practices
Matériaux pour image — Plaques photographiques développées —
Directives pour l'archivage
Reference number
ISO 18918:2000(E)
©
ISO 2000
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ISO 18918:2000(E)
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ISO 18918:2000(E)
Contents
Foreword.iv
Introduction.v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Photographic-plate housings: Storage enclosures and containers .3
4.1 Individual enclosures .4
4.2 Multiple-plate containers .4
5 Storage housings.5
5.1 Drawer cabinets .5
5.2 Shelving and cabinets.6
6 Storage rooms.6
6.1 Medium-term storage rooms .6
6.2 Extended-term storage rooms.6
7 Environmental conditions.6
7.1 Introduction.6
7.2 Temperature and humidity specifications for storage (see annexes D, E and F) .7
7.3 Environmental conditioning requirements .8
7.4 Air purity (see annex G) .8
8 Fire-protective storage (see annex H) .9
9 Photographic plate identification, handling and inspection (see annexes C, F and I) .9
9.1 Identification.9
9.2 Handling.9
9.3 Inspection.9
Annex A (informative) Numbering system for related International Standard.11
Annex B (informative) Photographic filing enclosures for plates.12
Annex C (informative) Silver-image degradation.13
Annex D (informative) Humidity during storage .14
Annex E (informative) Temperature during storage .15
Annex F (informative) Historic records for photographic plates .16
Annex G (informative) Air-entrained and gaseous impurities .17
Annex H (informative) Fire protection.18
Annex I (informative) Distinction between storage (record) copies and work (reference) copies .19
Bibliography.20
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ISO 18918:2000(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 18918 was prepared by Technical Committee ISO/TC 42, Photography.
This first edition cancels and replaces the fourth edition of ISO 3897:1997 of which it constitutes a technical
revision.
This International Standard is one of a series of standards dealing with the physical properties and stability of
imaging materials. To facilitate identification of these International Standards, they are assigned a number within
the block from 18900 to 18999 (see annex A).
Annexes A to I of this International Standard are for information only.
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ISO 18918:2000(E)
Introduction
Photographic plates on glass or metal supports have been in existence almost since the beginning of photography.
They have become increasingly important as documentary and pictorial reference material in archives, libraries,
government, commerce and academia.
The stability and useful life of processed photographic plates depends on their physical and chemical properties, as
well as on the conditions under which they are stored and used. This International Standard provides
recommendations on proper storage conditions and practices. Although it is difficult to distinguish between the
various types of plates covered by the definitions (see 3.7.1 to 3.7.8) with respect to storage life, the recommen-
dations may be applied to all processed photographic plates.
The important storage elements affecting the preservation of processed photographic plates are as follows:
� relative humidity and temperature of the storage environment;
� hazards of fire, water, and light exposure;
� fungal growth and other microorganisms;
� contact with certain chemicals in solid, liquid or gaseous form;
� physical damage.
The extent to which relative humidity and temperature, or variations of both, can be permitted to reach beyond
recommended limits without producing adverse effects will depend upon the duration of exposure, biological
conditions conducive to fungal growth, and the accessibility of the atmosphere to the surfaces.
The term “archival” is no longer specified to express longevity or stability in International Standards on image
materials, since it has been interpreted to have many meanings, ranging from preserving information “forever”,
which is unattainable, to temporary storage of actively used materials.
This International Standard defines two levels of recommended storage conditions: medium-term and extended-
term. Medium-term storage conditions can be used to preserve plates for a minimum of 10 years. Extended-term
storage conditions will prolong the life of all plates, even those not optimized for permanence.
The space requirements and costs for establishing and operating the two levels of storage conditions (medium-
term and extended-term) differ significantly. Furthermore, the specified limits of temperature and relative humidity
for both sets of storage conditions may not be realizable due to budgetary constraints, energy considerations,
climatic conditions, building construction, etc. However, it must be recognized that temperatures and relative
humidities which are higher than the specified conditions will reduce the effectiveness of the storage environment.
If such deviation is unavoidable, the environmental conditions closest to the specified limits should be provided. In
any event, the best preservation of plates will be attained with extended-term conditions.
The recommendations of this International Standard for processed photographic plates encompass the following:
� storage enclosures, housing and rooms;
� atmospheric and environmental conditions;
� fire protection;
� handling and inspection procedures.
This International Standard does not pertain to means or methods for protecting photographic plates against
natural or man-made catastrophes, with the exception of fire and its associated hazards; these are sufficiently
common to warrant inclusion of protective measures.
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INTERNATIONAL STANDARD ISO 18918:2000(E)
Imaging materials — Processed photographic plates — Storage
practices
1 Scope
1.1 This International Standard specifies dark storage conditions, storage facilities, and handling and inspecting
procedures for processed photographic plates having integral photographic layers and intended for record
purposes.
1.2 This International Standard is applicable to black-and-white, silver-image, gelatin, processed photographic
plates as defined in 3.7.7. It is also applicable to medium-term and extended-term storage conditions as defined in
3.6 and 3.2, respectively.
No specific distinction is made, other than the degree of care, between photographic plates for medium-term or
extended-term storage. Recommendations for plate storage relate to materials, methods, conditions, and forms of
protection applicable specifically to plates defined in 1.1. However, these storage recommendations may also be
applied to lacquered and opaque plates, to black-and-white plates altered by dyes or toners, colour plates and
other historic photographic plates defined in 3.7.2 to 3.7.8.
1.3 It is not intended to predict or assign a useful lifetime to processed photographic plates stored in accordance
with the specifications of this International Standard.
1.4 Recommendations for storage of photographic films are given in ISO 18911 and for storage of processed
photographic reflection print material in ISO 18920.
Although there is some variation in recommended storage conditions among these types of photographic materials,
recommended temperature and relative humidity ranges do overlap. If all three types of photographic materials are
found in one collection or within one storage area, the temperature and relative humidity should be chosen so that
all materials are stored within their recommended ranges.
2 Normative references
The following normative documents contain provisions, which, through reference in this text, constitute provisions
of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 14523:1999, Photography — Processed photographic materials — Photographic activity test for enclosure
materials.
1)
ISO 18902:— , Imaging materials — Processed films, plates and papers — Filing enclosures and storage
containers.
1)
ISO 18911:— , Imaging materials — Processed safety photographic films — Storage practices.
1)
ISO 18920: — , Imaging materials — Processed reflection prints — Storage practices.
1) To be published.
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ISO 18918:2000(E)
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
archival medium
recording material that can be expected to retain information forever, so that such information can be retrieved
without significant loss when properly stored
NOTE There is, however, no such material and it is not a term to be used in International Standards or system
specifications.
3.2
extended-term storage conditions
storage conditions suitable for the preservation of recorded information having a permanent value
3.3
fire-protective storage
facility designed to protect records against excessive temperatures, water and other fire-fighting agents, and steam
developed by insulation of safes or caused by the extinguishing of fires and collapsing structures
3.4
fire-resistant vault
fire-resistant vaults as defined in appropriate national standards and regulations
NOTE See [1] and [2] in the bibliography.
3.5
insulated record containers (Class 150)
insulated record containers (Class 150) as defined in appropriate national standards and regulations
NOTE See [3] and [4] in the bibliography.
3.6
medium-term storage conditions
storage conditions suitable for the preservation of recorded information for a minimum of 10 years
3.7
photographic layer
sensitive coating that yields an image after exposure to radiant flux
NOTE Exposure is usually followed by processing to generate the image.
3.7.1
photographic plate
material consisting of one or more radiation-sensitive layers coated on a rigid support, such as glass or metal, that
yields a visible image
3.7.2
albumen plate
glass sheet bearing a silver halide/albumen layer which yields a visible image after exposure and processing
3.7.3
ambrotype plate
glass plate collodion positive, i.e., a glass sheet bearing a thin silver halide/cellulose nitrate layer which yields a
visible image after exposure and processing
NOTE The processed negative silver image appears as a positive when backed by a dark field.
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ISO 18918:2000(E)
3.7.4
collodion plate
collodion wet or dry plate
glass sheet bearing a thin silver halide/cellulose nitrate layer which yields a visible image after exposure and
processing
3.7.5
colour screen plate
glass sheet bearing a colour screen consisting of dyed elements in contact with a silver halide/gelatin layer which
yields a visible image after exposure and processing
3.7.6
ferrotype plate
tintype
enamelled iron sheet bearing a thin silver halide/cellulose nitrate layer which yields a visible image after exposure
and processing
NOTE This is not to be confused with a thin metal sheet with a glossy surface upon which high-glass photographic prints
are dried.
3.7.7
gelatin plate
gelatin dry plate
glass sheet bearing a silver halide/gelatin layer which yields a visible image after exposure and processing
3.7.8
lantern slide
glass sheet bearing a silver halide/gelatin layer which yields a visible image after exposure and processing
NOTE The image layer of lantern-slide plates is usually protected with a cover glass, bound on all edges with adhesive
tape, as this type of plate is viewed by projection. Albumen and colour-screen plates are also found as lantern slides.
3.8
storage container
box or can used to store plates
3.9
storage enclosure
any item in close or direct contact with recording material such as folders, envelopes, sleeves, albums and mats
3.10
storage housing
physical structure that supports materials and their enclosures
NOTE It may consist of drawers, racks, shelves or cabinets.
4 Photographic-plate housings: Storage enclosures and containers
Processed photographic plates require protection against all types of physical damage such as scratches,
abrasion, fingerprints, breakage, etc. Filing enclosures and containers provide physical protection that minimizes or
prevents such damage. Processed photographic film and prints shall not be stored within the same enclosure or
container as photographic plates. Different types of photographic plates shall not be stored together within the
same enclosure or container, but instead shall be segregated by type (see definitions 3.7.2 to 3.7.8).
Enclosures and containers shall be designed to permit vertical storage of plates, resting on one long edge. Plates
shall not be stored in a flat or horizontal position since those on the bottom may be put under excessive pressure.
Plates made from 19th century glass are especially vulnerable to stress-related fractures when stored horizontally,
since such glass usually is not flat.
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ISO 18918:2000(E)
If unprotected plates are stored in contact, they shall be oriented with the emulsion side against the back side, not
emulsion against emulsion. However, unprotected plates with very fine-grain images should never be stored in
contact, but in grooved, multiple-plate containers of the type described in 4.2.
For maximum storage life, processed photographic plates shall be in a clean condition before they are placed in
storage.
4.1 Individual enclosures
All enclosures used for medium-term and extended-term storage shall meet the requirements of ISO 18902 and
ISO 14523. This includes enclosures that are in direct contact or in close proximity to the photographic plates.
Processed photographic plates may be stored in envelopes or sleeves, file folders, folding cartons, boxes, or
albums made from paper or plastic which meet the requirements of ISO 18902 and ISO 14523. Individual plates
should be placed in suitable individual envelopes (seamed or seamless types), sleeves or folders (see annex B) to
exclude dirt, to protect the plates against mechanical damage, and to facilitate identification and handling.
Suitable plastic enclosure materials are uncoated polyester (polyethylene terephthalate), polystyrene, polyethylene
and polypropylene. Other plastics may be satisfactory, but there has been no extended experience with such
materials. Glassine envelopes and chlorinated, nitrated, or highly plasticized sheeting shall be avoided. Specifi-
cally, cellulose nitrate and polyvinyl chloride are not acceptable.
The adhesive used for seams and joints shall also meet the requirements of ISO 18902 and ISO 14523. The filing
enclosure shall be constructed so that the seam or joint will be at the edge of the enclosure and not in contact with
the image layer. Adhesives that are suitable for use with paper include photographic-quality gelatin, some acrylic
and polyvinyl acetate adhesives, pure starch paste, and methyl cellulose.
4.2 Multiple-plate containers
Container materials should be metal, plastic or paperboard, and meet the specifications defined in ISO 18902 and
ISO 14523. The storage container materials shall be non-corrodible. Materials made of wood, pressed-board,
hardboard, particle-board, and other natural materials shall be avoided because they can contain oxidizing
materials which can attack the silver image (see annex C). Finishes on metal containers shall meet the criteria
listed in clause 5 for metal storage housings.
There are two types of multiple-plate containers, both of which are available in commonly used plate dimensions:
� standard document-storage containers for vertical storage of plates filed in contact with each other or a spacer
material;
� containers having grooved, parallel tracks for holding the plates apart in fixed, vertical positions.
The first type of container shall be designed to permit and maintain vertical plate storage on one long edge, as well
as allowing insertion and removal of plates without damage. This requires that the inner dimensions of the
container are only slightly larger than the plate size and that the strength and rigidity of the container are
commensurate with the weight of a full complement of plates. Rigid paperboard inserts or filler pieces meeting the
requirements of ISO 18902 and ISO 14523 can be used to ensure that plates are kept upright and to prevent them
from rubbing against each other.
The second type of container shall be used when it is necessary to avoid plate-to-plate contact, as in the case of
plates having a very fine-grain image or when plates are not protected by either individual enclosures or a cover
glass. Such containers normally are lined on the bottom and sides of the interior with inserts that have parallel
grooves. The grooves have a U- or V-type cross-section to restrict contact at the extreme edges of the plates while
holding the plates vertical.
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ISO 18918:2000(E)
5 Storage housings
Processed photographic plates should be stored in closable storage housings such as vertical filing drawers or
cabinets, in storage cabinets with tightly fitting doors, or inside closed containers on open shelves. Storage
housings for photographic plates should be designed to bear a heavy weight load. Plates or plate containers should
be placed so that their weight is centred on the shelving or inside the drawer, thus minimizing the tendency of the
shelving or cabinets to topple over due to uneven weight distribution. Storage housings may be bolted to floors and
wall studs as an added precaution to secure against the danger of tipping over.
The materials used in the fabrication of storage housings should be non-combustible, non-corrosive, and
chemically inert, for example, anodized aluminium, stainless steel, or steel finished with a non-plasticized synthetic
resin-powder coating. Wood, pressed-board, particle-board, plywood, and other such materials shall be avoided
because of their combustible nature and the possibility of their producing active deteriorating agents as they age.
The finish on the storage housing materials should be durable and should not contain substances that can have a
deleterious effect on the stored plates. Adverse effects may be produced by finishes containing chlorinated or
highly plasticized resins, or by solvents off-gassing from freshly applied finishes. Paints used on cabinets may give
off peroxides, solvents, and other contaminants for up to three months after being applied. Metal housing materials
that have been powder-coated (a solvent-free finish process in which electrostatically applied resin particles are
fused by heat), or cabinets made from stainless steel or anodized aluminium, are recommended.
When air that is temperature- and humidity-conditioned is supplied to storage housings, adequate interior air
circulation shall be provided to all shelves and drawers holding plates or their containers, to ensure proper and
uniform temperature and relative humidity conditions. Storage housings located in rooms that are properly air-
conditioned in accordance with 7.2 shall be vented to permit adequate air circulation within the interior of the
housing. Such openings shall not interfere with the requirements for fire-protective storage or water protection.
Photographic reflection prints and film may be stored within the same storage area as processed photographic
plates, but not in the same enclosure or storage container. Magnetic tapes and optical disks shall not be stored
within the same storage area or housing as photographic plates due to possible deleterious effects of off-gassing
during storage.
5.1 Drawer cabinets
Structurally reinforced, modified office-type filing cabinets with drawers are suitable for storing individual
photographic plates when the following handling precautions are observed:
� care is taken to avoid uneven weight distribution and potential toppling of the cabinet when the upper drawers
are opened all the way;
� drawers are opened and closed slowly and smoothly to avoid jostling the plates inside.
The drawers should be flat-bottomed and the vertical height of the drawer should be slightly larger than the vertical
dimension of the plates. Drawers should be fitted with rigid vertical dividers that are the same height as the plates.
Dividers should be fixed at appropriate intervals, for example, 2,5 cm to 5 cm and not more than 10 cm. In addition
to supporting the plates, the dividers minimize movement of plates during retrieval and filing and relieve pressure
on plates located at the end of rows.
Plates should be grouped by size and shall be filed vertically in the drawers, in one or more parallel rows
depending on the plate size. Rows should be divided by suitable partitions. If drawers are not fitted with rigid
dividers, containers can be used as a means of grouping plates within compartments in order to minimize jostling,
and as an aid to organization and filing.
Structurally reinforced drawer-type cabinets are also recommended for storing plate containers as described in 4.2.
Containers should be filed in a single layer, i.e., not stacked on each other. Care should be taken to ensure that
containers do not tip over when other containers are removed during use.
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ISO 18918:2000(E)
5.2 Shelving and cabinets
Multiple-plate containers may also be stored on open-sided shelving or racks, or in door-type cabinets equipped
with shelving or racks. The spacing between shelves should allow safe retrieval and filing of containers. Containers
should be filed in a single layer, i.e., not stacked on each other, with the plates oriented vertically. The shelves
should be divided by partitions, arranged to accommodate several containers, in order to keep the containers
upright during retrieval and refiling. Care should be taken to ensure that containers do not tip over when other
containers are removed during use.
Door-type cabinets with shelving may be used for storing individual plates. Shelves should be fitted with rigid
vertical dividers that are the same height as the plates. Dividers should be fixed at appropriate intervals, for
example, 2,5 cm to 5 cm and not more than 10 cm. In addition to supporting the plates, the dividers minimize
movement of plates during retrieval and filing and relieve pressure on plates located at the end of rows. Plates
should be grouped by size and filed vertically.
6 Storage rooms
6.1 Medium-term storage rooms
Rooms and areas used for plate storage should be located in the same area as rooms containing provisions for
inspection and viewing of the photographic plates. Good housekeeping is essential. Walls and enclosed ai
...
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