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SPA N DAR D
6051
Third edition
1992-12-15
Photography - Processed photographic paper
prints - Storage practices
Photographie - Papiers photographiques traités - Directives pour
l’archivage
Reference number
IS0 6051 : 1992( E)
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IS0 6051:1992(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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, govern-
mental and non-governmental, in liaison with ISO, also take part in the
work. IS0 collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an Interna-
tional Standard requires approval by at least 75 Oh of the member bodies
I
casting a vote.
I
International Standard IS0 6051 was prepared by Technical Committee
ISO/TC 42, Photography.
I This third edition cancels and replaces the second edition
(IS0 6051:1986), of which it constitutes a technical revision.
Annexes A, B, C, D, E and F of this International Standard are for infor-
mation only.
O IS0 1992
All rights reserved. No part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanlcal, including photocopying and microfilm, without
permlsslon In writing from the publisher.
International Organization for Standardization
Case Postale 56 * CH-1211 Genève 20 Switzerland
Printed in Switzerland
ii
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IS0 6051:1992(E)
Introduction
Photographic paper prints are important documentary and pictorial ma-
terials. There is a recognized need for information on safeguarding
photographic prints having legal, scientific, industrial, artistic or histor-
ical value. The value of such records used in archives, museums, Ii-
braries, government, commerce and universities has focused attention
on the care of such records to ensure their longest possible life [Il.
Photographic prints are susceptible to degradation from many sources.
The factors can be divided into three general categories.
a) Nature of the photographic print
The stability of photographic print records depends on the physical
and chemical nature of the print. Excellent keeping experience has
been obtained with numerous photographic prints for a great many
years. However, as yet no International Standard has been drafted
on the stability of different types of photographic prints.
b) Photographic processing of the print
For silver-gelatin type paper prints, the effect of residual thiosulfate
will form the subject of a future International Standard.
c) Storage conditions
The conditions under which photographic paper prints should be
stored are extremely important for the preservation of prints and are
the subject of this International Standard.
The important elements affecting preservation of processed prints
are humidity, temperature and pollutants of the air, as well as the
hazards of water, light, fungal growth, insects, microbiological attack,
contact with certain chemicals in solid, liquid or gaseous form, and
physical damage.
The extent to which humidity, temperature, pollutants or variations
thereof can be permitted to reach beyond recommended limits with-
out producing adverse effects will depend upon the duration of ex-
posure, on biological conditions conducive to fungal growth, and on
the accessibility of this atmosphere to the print surfaces.
The recommendations of this International Standard also pertain to
fire protection, print handling and inspection. This International
Standard does not give recommendations concerning protection
against natural or man-made catastrophes with the exception of fire
and associated hazards which are sufficiently common to warrant
inclusion of protective measures.
In addition to the specifications in this International Standard, good
storage practices should consider the filing enclosure. These are
covered in IS0 10214.
iii
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INTERNATIONAL STANDARD IS0 6051:1992(E)
Photography - Processed photographic paper prints -
Storage practices
1 scope
2 Normative reference
The following standard contains provisions which,
0
through reference in this text, constitute provisions
1 .I This International Standard aives recommen-
of this International Standard. At the time of publi-
dations concerning the storage conditions, storage
cation, the edition indicated was valid. All standards
facilities, handling and inspection for all processed
are subject to revision, and parties to agreements
photographic paper prints in roll, strip, or sheet
based on this International Standard are encour-
form, regardless of size.
aged to investigate the possibility of applying the
most recent edition of the standard indicated below.
This International Standard applies to wet processed
Members of IEC and IS0 maintain registers of cur-
silver-gelatin, thermally processed silver, diazo and
rently valid International Standards.
colour papers.
IS0 10214:1991, Photography - Processed photo-
graphic materials - Filing enclosures for storage.
1.2 The storage of photographic film and photo-
graphic plates requires different considerations and
these are not covered in this International Standard
3 Definitions
but are covered in IS0 5466 and IS0 3897, reçpect-
ively.
For the purposes of this International Standard, the
fo I low i n g d efi n it ions a p p I y.
1.3 This International Standard applies to photo-
3.1 photographic paper print: Paper sheet having
@ graphic paper records intended as storage copies;
a photographic image on a base consisting largely
these copies being used only infrequently. It does
of cellulose fibres.')
not apply to work copies.
3.2 fire-protection storage: Facilities designed to
protect photographic prints against excessive tem-
peratures, water and other fire-fighting agents,
1.4 This International Standard, while intended for
steam developed by insulation of safes, and coi-
materials that are well processed, should also be of
lapsing structures.
considerable value in prolonging the useful life of
photographic paper prints whose processing con-
3.3 insulated record container: Container as de-
ditions are unknown, or that have been toned,
fined in appropriate national standards and regu-
mounted, retouched or bear markings with materials
I at ion s .2)
of uncertain or unknown stability. It is not intended
to predict or assign a useful lifetime to photographic
prints stored in accordance with the specifications 3.4 fire-resistant vault: Vault as defined in appro-
of this International Standard. priate national standards and regulation^.^)
1) The photographic image may be in a layer coated either directly on the paper or on a pigmented layer (RC) previously
or on a resin layer (RC) previously applied to the paper. The photographic image may also be de-
applied to the paper,
posited on the paper surface without a binder layer.
2) Example: Class 150 of UL 72 C23.
3) Example: NFPA 232 [JI.
1
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IS0 6051 :1992(E)
3.5 open enclosure: Enclosure which is intended of the ambient air shall not exceed the rec-
for physical protection against mechanical damage ommended limits.
but neither lighttight nor airtight.
Enclosures shall be non-corrodible, peroxide-free
Folders, envelopes, cartons, sleeves, albums, wrap- and not highly plasticized as described in IS0 10214.
pers or jackets are examples of open enclosures. Rubber bands shall not be used for confining paper
on reels or cores. If paper bands are used, the paper
shall meet as a minimum requirement the specifi-
3.6 protective enclosure: Lighttight, impermeable
cations described in IS0 10214.
container used for protection from outside factors
such as reactive gases and moisture, including
relative humidity changes.
4.3 Protective enclosures
Sealed envelopes are examples of protective en-
Protective enclosures shall be used where needed
closures.
to maintain humidity within the limits specified (see
clause 7), to protect against gaseous impurities in
4 Print enclosures the atmosphere, or when low-temperature storage
is used. Heat-sealable envelopes consisting of
aluminium foil extrusion coated with clear poly-
4.1 Classification of enclosures
ethylene on the inside and laminated to a suitable
paper sheet on the outside have been successfully 0
Enclosures used for long-term storage of sheets or
used as sealed enclosures. To provide greater pro-
rolls of processed photographic paper prints may be
tection against pinholes, a double-bagging tech-
divided into two broad classifications: open enclos-
nique is recommended. Precautions should be taken
ures and protective enclosures.
in handling these envelopes so that they are not
punctured.
4.2 Open enclosures
Suitable enclosures for rolls of photographic paper
are closed containers made from impermeable ma-
The purpose of open enclosures is to exclude dirt,
terials with friction-type or threaded, twist-on lids
to protect the print against mechanical damage and
having an incorporated seal. Rubber gaskets shall
to facilitate identification and handling. They give
not be used. Flip-top, hinged or telescoping lids can
limited access to ambient air. Therefore, the con-
be used, but the joint shall be sealed by several
ditions of the surrounding air should be within the
wraps of pressure-sensitive adhesive tape having
recommended limits of 7.1 to 7.4.
low gas permeability. Taped cans within heat-sealed
foil bags provide additional protection from high hu-
Prints in sheet form may be stored in envelopes of
midity. If tape is used, routine retaping of joints ev-
paper or plastic foil, folding cartons, file folders, or
ery 2 years is recommended; in any case if the tape
in strip jackets. Colour prints shall be stored in
seal is observably deficient in integrity, it shall be
opaque envelopes or folders or otherwise protected
replaced.
from light exposure. When in direct contact with the
surface of the photographic print, the paper or plas-
a
tic material used for envelopes, sleeves, jackets,
5 Storage housings
folders and cartons shall meet as a minimum re-
quirement the specifications described in IS0 10214.
Photographic prints should be stored in closed
Adhesives used in open enclosures shall also meet
housings such as drawers, or on shelves and racks
the requirements described in IS0 10214. The filing
enclosed by doors to provide protection from dust
enclosure shall be constructed so that any seam or
and dirt. Alternatively, open shelves and racks may
joint will be at the edge of the enclosure and not in
be used if the prints are in closed containers. The
contact with the print surface. For maximum storage
storage housing materials shall be non-combustible
life, photographic prints shall be in a clean condition
and non-corrodible as described in IS0 10214. Be-
before being placed in storage.
cause of their combustible nature and the possibility
Prints which have labels on them, or which have
of producing active fading agents on ageing, me-
been annotated, particularly with felt-tip pens, shall
ierials made of wood, pressed-board, hardboard,
be interleaved with protective paper. particle-board and other natural materials shall be
avoided.
Rolls of photographic paper should be preferably
stored in closed enclosures to provide protection The finish on housing materials shall be durable and
against dirt and physical damage. Suitable enclos-
shall not contribute deleterious effects to the stored
ures are those with telescoping, slip-type or photographic prints. Adverse effects can be pro-
threaded twist-on lids. Closed enclosures are not duced by finishes containing chlorinated or highly-
necessarily airtight and can give limited access to plasticized resins, or by freshly-painted or lacquered
ambient air. Therefore, if they are used, the humidity surfaces. Cabinets painted with oil-base paints shall
2
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IS0 6051:1992(E)
not be used for 3 months afier painting as they can fects on the image stability of photographic prints,
give off peroxides. High moisture content of the air is conducive to
mould growth which can completely destroy the im-
When air-conditioned individually, storage housings
age in time; and also the higher the moisture level,
shall be arranged to permit interior circulation of air
the greater is the effect of residual chemicals. A
to all shelves and drawers holding prints to allow
relative humidity lower than 30 ?Ao will minimize
uniform humidity conditions. Storage housings lo-
chemical deterioration, but can cause emulsion
cated in rooms conditioned in accordance with 7.1
brittleness and print curl in the material stored.
shall be provided with ventilation openings permit-
These latter effects may, however, be partially re-
ting access of air to the interior. Such openings shall
versed by reconditioning to the proper humidity
not affect accordance with requirements for fire-
level.
protection storage or water protection.
Caution should be exercised in storing paper prints
7.2 Temperature limits (see annex B)
whose processing conditions are unknown or which
have been treated or marked with materials of un-
Probably the most important aspect of temperature
known stability. Intermixing of such prints with un-
is its effect on relative humidity, since a temperature
altered prints known to have been well processed in
variation may take the relative humidity beyond the
the same storage housing should be avoided.
acceptable range. Photographic papers shall not be
stored above 30 OC for a prolonged period. This high
temperature will accelerate the reactions that de-
@ 6 Storage rooms
grade the image. A temperature in the range of
15 OC to 20 OC is acceptable but daily cycling greater
Rooms and areas used for print storage should be
than 4 OC shall be avoided, by thermostatic means
associated with rooms allowing facilities for in-
if necessary.
spection and viewing of the print. The inspection
area should be maintained at the same temperature
Added protection may be obtained for all prints by
and humidity as the storage room, to avoid curling
low temperature storage. A storage temperature of
or distortion. Good housekeeping is essential. Walls
2 OC or below is strongly recommended for colour
and enclosures of air-conditioned spaces shall be
images E41 C51. Two methods may be used as fol-
designed to prevent condensation of moisture on
lows.
interior surfaces and within walls, especially during
periods of low exterior temperatures when the walls
a) The prints may be conditioned to the rec-
can be cooled below the dew point of the air. Pro-
ommended relative humidityd), placed in
visions shall be made against print damage by wa-
hermetically-sealed enclosures after excluding
ter from floods, leaks, sprinklers, etc. Storage rooms
as much air as possible, and then placed in
or vaults should be located above basement level,
below-freezing storage. Prints may be placed
where possible.
within two heat-sealed bags to provide good
moisture protection. The use of such bags im-
The value of photographic prints kept for long peri-
proves moisture protection but does not guaran-
ods of time makes it advisable to provide a storage
tee it. This procedure has the advantages of
room or vault separate from temporary storage fa-
excellent keeping conditions and the use of
cilities, offices or work areas. It should be located
reasonably-priced deep-freeze units. It is essen-
as far as possible from an urban or industrial area
tial to limit as much as possible the volume of
where contaminants (see 7.3) may be present i
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