ISO/TC 42/WG 5 - Physical properties and image permanence of photographic materials

This document specifies test method, test target, and reporting requirements to determine the scratch resistance of prints with photographic images. Photographic images can be produced by a wide range of printing technologies, including silver halide, electrophotography, inkjet, dye diffusion thermal transfer, commonly known as dye sublimation, and dye transfer processes. This document is applicable to prints with paper substrate and other type of substrates including prints on plastic, glass, metal and other materials. This document is applicable to photographic prints that have no protection as well as photographic prints that are protected by a coating or lamination. It is not the purpose of this document to define limits of acceptability or failure. They would be determined by the user and the intended application.

This document describes test methods for determining the long-term dark storage stability of colour photographic images and the colour stability of such images when subjected to certain illuminants at specified temperatures and relative humidities. This document is applicable to colour photographic images made with traditional, continuous-tone photographic materials with images formed with dyes. These images are generated with chromogenic, silver dye-bleach, dye transfer, and dye-diffusion-transfer instant systems. The tests have not been verified for evaluating the stability of colour images produced with dry- and liquid-toner electrophotography, thermal dye transfer (sometimes called dye sublimation), ink jet, pigment-gelatin systems, offset lithography, gravure and related colour imaging systems. If these reflection print materials, including silver halide (chromogenic), are digitally printed, refer to ISO 18936, ISO 18941, ISO 18946, and ISO 18949 for dark stability tests, and the ISO 18937 series for light stability tests. This document does not include test procedures for the physical stability of images, supports or binder materials. However, it is recognized that in some instances, physical degradation such as support embrittlement, emulsion cracking or delamination of an image layer from its support, rather than image stability, will determine the useful life of a colour film or print material.

This document establishes a vocabulary of terms and definitions used in respect of the permanence of imaging materials, related storage materials and digital storage media. In most cases these terms and definitions are generic and are applicable to the entire imaging industry. For terms and definitions specific to particular applications, refer to industry standards. However, in some cases the definition of a term is still evolving and/or is used by different user groups in different ways. In this case a definition fit for use in Imaging Materials – Permanence work is given and a note to this effect is included.

The test method in this document is intended to be used to characterize and compare the degradation of a set of print materials under exposure to particular light sources, eventually including optical filter combinations, under museum environmental conditions. The document covers typical types of indoor light sources commonly found in a museum including indoor daylight, LED, and incandescent light. This document is applicable to analogue and digital reflection photographic prints. NOTE Examples of photographic prints covered by this document are prints made with digital printing technologies such as inkjet, electrophotography, and thermal dye transfer, as well as prints made on silver halide colour paper but not prints made on black and white silver halide paper.

This document specifies tests to determine the abrasion resistance of photographic images for typical use in indoor context that is characterized by mild abrasive conditions. Examples are flipping of pages in an album, careful manual handling of prints (stacking, shifting) or use of magnets for attachment to a board. Photographic images refer to individual prints or prints in albums, which can be produced by a wide range of printing technologies, including silver halide, electrophotography, inkjet, dye diffusion thermal transfer, commonly known as dye sublimation, and dye transfer processes. Photographic images require “photo-grade” media, including coated or surface treated print materials, which are prerequisite to obtain photographic quality with aforementioned printing technologies. Test procedures are limited to (quasi-) linear, reciprocal abrasion test devices. For other printing technologies (e.g. offset lithography and other photomechanical printing processes) or non-photo-grade media or other levels of rubbing representative of other application profiles, different test methods and/or device options may be considered (see ISO 18947‑1). Heavy duty abrasive conditions, such as floor tiles, floor graphics, abrasive cleaning and vehicle graphics, are out of scope of this document.

This document describes test methods for determining the long-term dark storage stability of colour photographic images. It is applicable to colour photographic images made with traditional photographic materials. These images are generated with systems such as chromogenic, silver dye-bleach, dye transfer, dye-diffusion-transfer "instant", and similar systems. The test method specified in this document also covers the dark-stability of digital colour images produced with dry- and liquid-toner electrophotography, thermal dye transfer (sometimes called "dye sublimation"), and inkjet printing systems.

This document describes the equipment, methods and procedures for generating a known ozone exposure and the subsequent measurement and quantification of the amount of change produced within both digitally printed hardcopy images and traditional analogue photographic colour print images due to that exposure. The test method described in this document uses increased levels of ozone to achieve an accelerated test. If the principal "gas fading" mechanism for a system is not ozone, this method might not be suitable and might give misleading results as to resistance of the test image to polluted air.

This document describes test methods to evaluate reflection colour photographic prints with regard to changes in image appearance resulting from exposure to low relative humidity. The observed changes relate primarily to substrate yellowing. Other observed humidity related physical damage factors such as curl, cockle, cracking, or delamination due to humidity cycling are also within the scope of this test method.

This document specifies test methods to assess the permanence and durability of photo books, including cover and pages. This document is applicable to photo books which contain reflection colour prints made with colour hardcopy materials of all types, including those from either traditional analogue printing or modern digital printing processes. The same performance test methods apply, regardless of the printing process. Because of the large number of combinations of sizes, cover materials, binding options and printing processes, testing of all possible combinations is not within the scope of this document. Instead, a representative selection of printed pages, cover materials and binding options that are used in the makeup of the photo book are tested.

This document describes the experimental framework, results, and conclusions from a round robin test that was performed in order to establish correlations between accelerated weathering according to the ISO 18930 test method and outdoor weathering at nine outdoor sites. The types of digital printing technology that were used in this round robin test are aqueous inkjet, solvent inkjet, UV curable inkjet, digitally-exposed silver halide, and thermal mass transfer. The image print stability data and correlations of this document are to be considered illustrative of the performance of these classes of materials. Extension of these correlations to other classes of materials, such as dye sublimation, is verified by appropriate experimentation.

This document specifies tests to determine the relative water resistance of printed colour images. This document is applicable to both digital and analogue prints.

This document specifies requirements and recommendations for the digital test file content, printer setups and printing procedures that are used to generate target prints for test method standards and specifications for image stability in the context of reflection colour photographic prints. Furthermore, this document defines measurement procedures of the test patches as well as how changes of colour attributes are calculated in the course of a given image stability test. Definition of the statistical procedure for data reduction and the translation of those changes into psychophysical end point levels does not belong to the scope of this document, but results obtained with the methods defined in this document can feed into the appropriate statistical evaluation and end point systems of a print life specification defined in other documents.

ISO 18943:2014 concerns the storage, care, and handling of HDDs. It recommends handling procedures to maximise the effective life of the data written on magnetic HDDs. Faulty care and handling methods can cause damage to a disk and the contents written thereon. It also recommends storage practices to preserve both the hard disk media and the content encoded thereon. The recommendations in this International Standard apply where the desired result is extended-term retention of the data encoded on the disk. The use of the phrase "care and handling" in this International Standard is restricted to the physical domain or hardware aspects of the HDD. This International Standard is not intended to address associated or relative system aspects of HDDs. With recognition that the scope of systems is covered in other standards, this International Standard precisely aims to fill a void of information on HDDs as physical media with failure mechanisms and handling risks. This International Standard does not promote or advocate that proper physical care and handling represents the only element on the path to extended-term usage (more than two years), but rather is part of a comprehensive set of practices to mitigate risks in the long term preservation of content stored on HDDs.

ISO 18938:2014 establishes general principles for the care and handling of digital optical discs during use. It addresses the issues of physical integrity of the medium necessary to preserve access to the recorded data (information). ISO 18938:2014 includes recommendations for handling procedures to maximize the effective life of optical discs. The following are within the scope of ISO 18938:2014: use and handling environments, including pollutants, temperature and humidity and light exposure; contamination concerns; inspection; cleaning and maintenance, including cleaning methods and frequency; transportation; disasters, including water, fire, construction and post-disaster procedures; staff training.

ISO 18939:2013 establishes test methods for measuring the stability of photographic films intended for storage of medical records. It is applicable to greyscale images on films for use in transmission mode that are based on thermally processed materials (photothermography, thermography, microcapsule) or created by inkjet printing. Thermally processed materials have a base of safety polyester [poly (ethylene terephthalate)] and work predominantly with silver behenate salts dispersed in non-gelatinous emulsions or dye-based microcapsule emulsions that are thermally processed to produce a black-and-white image. In inkjet printing ink droplets are jetted onto a film with an ink-receiving layer to produce a greyscale image. ISO 18939:2013 does not cover wet-processed black-and-white films or black-and-white paper. It is not applicable to medical colour images or colour prints created by colour inkjet or dye diffusion thermal transfer (D2T2). Neither does it cover medical greyscale images printed on reflective materials for referral purposes or filmless systems such as picture archiving and communication systems (PACS) in medical imaging. ISO 18939:2013 requires the arbitrary choice of "illustrative end points" for changes in colour and perceived contrast to depict quantifiable changes due to physical ageing. Extrapolations based on ?illustrative end points' do not have any proven diagnostic or clinical relevance due to the lack of corresponding statistically significant scoring by radiologists.

ISO 18902:2013 specifies the principal physical and chemical requirements for album, storage and framing materials to prevent damage to processed or printed imaging materials over time. It covers requirements for: paper and paperboard; plastics; metals; writing instruments; adhesives; tapes; self-adhesive labelling materials; stamping inks and pads; framing and glazing materials used as, or in the construction of, storage and display materials for black-and-white or colour reflection prints or negatives made with traditional silver-halide and silver dye bleach photographic materials; dye- and pigment-based inkjet, dye diffusion thermal transfer ("dye sublimation"), and liquid- and dry-toner electrophotographic digital prints.

ISO 18927:2013 specifies a test method for estimating the life expectancy of information stored on recordable compact disc systems. Only the effects of temperature and relative humidity on the media are considered.

ISO 18928:2013 specifies recommended storage conditions for unprocessed photographic materials. ISO 18928:2013 is applicable to black-and-white and colour photographic materials (negative films, positive films, reversal films, positive papers, and X-ray films), as well as to safety films.

ISO 18914:2013 specifies a laboratory test method for determining the resistance of photographic emulsions or gelatin backings to abrasion damage during processing. This method may be used to determine the effects of variations in processing solutions, gelatin layer properties, processing solution temperatures and times, or a combination of these factors, on the wet scratch resistance of gelatin layers. This method is applicable to the determination of the physical integrity of photographic emulsions when wet.

ISO 18907:2013 specifies a method for determining and expressing quantitatively the brittleness of photographic film and papers. The method is applicable to films with or without a gelatin backing and to fibre-based or resin-coated (RC) photographic papers. It may also be applied to either raw or processed materials.

This International Standard establishes extended-term storage conditions for optical discs and provides recommendations concerning the storage conditions, storage facilities, enclosures, and inspection for optical discs. It is applicable to discs made for audio, video, instrumentation, and computer use. Recommendations are general in nature and it is advisable that the manufacturer's cautions for specific material be considered. Relaxation from these recommendations, whether before or after recording, will generally result in shortened life expectancy.

ISO 18924:2013 specifies a test method for the prediction of certain physical or chemical property changes of imaging materials. ISO 18924:2013 is applicable to the Arrhenius test portion of ISO 18901, ISO 18905, ISO 18909, ISO 18912 and ISO 18919. ISO 18924:2013 is applicable to the prediction of the optical-density (D) loss or gain of imaging materials. Photographic dye images may be produced by chromogenic processing, by formation of diazo dyes, or by non-chromogenic methods such as dye diffusion and silver dye-bleaching processing. ISO 18924:2013 also covers density changes caused by residual coupler changes in dye images, excess residual processing chemicals in silver black-and-white materials, temperature effects on thermally processed silver images. This International Standard is applicable to the prediction of support degradation.

ISO 18926:2012 specifies a test method for estimating the life expectancy (LE) of information stored on rewritable and write-once magneto-optical media. Only the effects of temperature and relative humidity on the media are considered.

ISO 18929:2012 establishes the specifications for silver-gelatin photographic reflection prints intended for dark storage. It covers silver-gelatin print types of all weights. ISO 18929:2012 applies to wet-processed black-and-white silver-gelatin photographic prints, including those that have been chemically treated (with a gold, selenium, sulfur, or other chemical treatment bath) to improve the permanence of the silver image. It also applies to silver-gelatin prints processed by a monobath, which includes thiosulfate as a fixing agent followed by a conventional wash.

ISO 18946:2012 describes test methods for evaluating reflection colour photographic prints with regard to changes in image appearance resulting from exposure to both low and high relative humidity. The observed changes relate to colour, tone and loss of sharpness caused by horizontal and vertical diffusion of colorants from exposure to elevated humidity levels. Other humidity-related factors are outside the scope of this test method. The method and procedures described in ISO 18946:2012 are particularly appropriate to systems where the colorants are applied by a mechanism involving the diffusion of colorant into image-receiving layers and to certain types of inkjet media that are susceptible to Dmin yellowing.

ISO 18934 provides suggested guidelines for four temperature and humidity macro-environments for archives that contain a variety of recording media, based on the corresponding ISO storage standards for those media. Whenever possible, ISO 18934 recommends that users follow the storage environments in the ISO storage standards. ISO 18934 does not replace those ISO storage standards. In addition to environment recommendations, those standards also include other vital information pertinent to the long-term keeping of recording materials, such as inspection, housing, and handling guidelines. Although microenvironments within a storage enclosure can be dependent upon the macro-environment, they are not the focus of ISO 18934. The storage of traditional paper collections is not within the scope of ISO 18934. Nitrate‑base photographic films are also included in ISO 18934, since they are often stored together with other materials. ISO 18934 does not address the various strategies to upgrade substandard environments that deviate from those recommended by ISO standards.

This International Standard describes test equipment and test procedures for determining the colour stability of photographic colour images when subjected to outdoor conditions. It does not specify limits of acceptability or failure criteria. Instead, it provides means for measuring image changes that take place during the aging of pictorial photographic images and indicates the critical image-change parameters that should be reported. Users of this International Standard should determine which test end-points best simulate the intended display application. This International Standard is applicable to pictorial images made with digital printing media, for example: — prints on coated papers, coated and uncoated clear and opaque films, vinyl, polyester, synthetic papers and other plastic substrates, laminated and not laminated; — dye-based and pigment-based inkjet prints with aqueous, solvent, phase-change, or UV curing inks; — thermal dye and mass transfer; — dye sublimation prints; — digitally-printed dye-diffusion-transfer prints; — liquid- and dry-toner xerographic prints; — liquid toner electrostatic prints; — digitally printed images made with traditional chromogenic and silver dye-bleach photographic materials; — colour direct thermal prints. In these digital printing processes, the ink laydown is controlled by means of digital pixel information, and all of the settings and controls of the printing system can be documented and repeated. In contrast, for many analogue printing systems, the control over the ink film thickness can be subject to manual adjustment. Window graphics on the outside of windows are covered by this International Standard. Window graphics on the inside of windows, for which sunlight is filtered by a layer of glass, will be covered by ISO 18937. This International Standard does not include test procedures for physical stability of images, supports or binder materials. However, it is recognized that in some instances physical degradation such as support embrittlement, image layer cracking, or delamination of an image layer from its support, rather than image stability, will determine the useful life of a print material. NOTE Image print stability results determined for one printer model, ink set, printing mode, print resolution and media combination are not applicable to image prints produced through another printer model, ink set, printing mode, print resolution and media combination, even if the ink jet cartridges and/or media used in testing are the same.

ISO 18920:2011 specifies dark storage conditions, storage facilities and procedures for the handling and inspection of reflection prints of all types and sizes. ISO 18920:2011 is applicable to: · prints on opaque supports, · processed black-and-white silver gelatine prints, · processed multicolour and monochrome colour photographic prints, · black-and-white and colour prints. ISO 18920:2011 is applicable to medium-term and extended-term storage conditions.

ISO 18911:2010 provides recommendations concerning the storage conditions, storage facilities, handling and inspection for all processed safety photographic films in roll, strip, aperture‑card or sheet format, regardless of size. ISO 18911:2010 is applicable to extended‑term and medium‑term storage of photographic film. ISO 18911:2010 is applicable to photographic film records intended as storage copies, which are not in frequent use. It does not apply to “work” or “use” copies. ISO 18911:2010, while intended for materials that are properly processed, is also of considerable value in prolonging the useful life of photographic film whose processing conditions are unknown, or which has been toned or retouched, or has markings with materials of uncertain or unknown stability. ISO 18911:2010 is applicable only to safety photographic film (see ISO 18906). Nitrate-base films are not covered by ISO 18911:2010. The storage of photographic prints and photographic plates requires different considerations. They are not covered in ISO 18911:2010, but are described respectively in ISO 18920 and ISO 18918.

ISO 18901:2010 establishes the specifications for photographic films intended for the storage of records. ISO 18901:2010 is applicable specifically to films with a base of safety cellulose ester or polyester having silver-gelatin emulsions, processed to produce a black-and-white silver image by negative or full-reversal processing. It applies to film processed using a monobath that includes thiosulfate as the fixing agent, followed by a conventional wash. It also is applicable to silver films given a stabilizing treatment by partial or full conversion to silver sulfide, silver selenide or gold. ISO 18901:2010 is applicable to films having ultrasonic or dielectric (induction-heated) splices. It does not cover films with splices made of adhesive tape or solvent-type spIices. ISO 18901:2010 is not applicable to films with chromogenic black-and-white images, colour images of any type, or to films with a magnetic recording track. It does not apply to films with silver images produced by dry or thermal processing or by diffusion-reversal processing, or to films that have been processed by a monobath using means other than a thiosulfate-type fixing solution. It is not applicable to films where the silver salts are removed by means other than thiosulfate solutions. ISO 18901:2010 is not applicable to films to which lacquers have been applied.

ISO 18932:2009 provides specifications for adhesive mounting materials for use in attaching prints, including photographic, electrophotographic, electrostatic, thermal transfer or inkjet prints to mounting boards, album leaves, file cards and other supports. ISO 18932:2009 covers both pressure-sensitive and thermally-activated adhesives. Spray adhesives are specifically excluded from ISO 18932:2009.

ISO 18921:2008 specifies a test method for estimating the life expectancy (LE) of information stored on compact disc (CD-ROM) media, including CD audio, but excluding recordable media. Only the effects of temperature and relative humidity on the media are considered.

ISO 18916:2007 specifies the procedure for the photographic activity and dye coupler reactivity tests. ISO 18916:2007 is applicable to general photographic enclosure materials such as paper, tissue, cardboard, mat board and plastics. It is also applicable to components of photographic enclosure materials such as adhesives, inks, paints, labels, and tape. ISO 18916:2007 evaluates possible chemical interactions between enclosures with processed silver-gelatin, colour (dye-gelatin), inkjet prints made with dye-based and pigment-based inks, thermal dye diffusion transfer (“dye sub”) prints, digitally printed dye-diffusion-transfer prints, liquid- and dry-toner xerographic prints, liquid-toner electrostatic prints, and diazo images after long-term storage. It does not pertain to harmful physical interactions such as blocking (sticking together), dye bleed, adhesive migration, or plasticizer exudation. It does not pertain to important criteria of enclosures such as their inherent chemical stability, physical integrity, and workmanship. Passing the photographic activity test (PAT) does not indicate that a material is archival. This term has no clear definition and is not used in this standard. Photo-safe, storage enclosures and their components are covered in ISO 18902, which includes passing the criteria of the photographic activity test. If a particular brand of commercially made enclosure materials is found to be safe for long-term storage purposes, there is no assurance that subsequent batches will contain the same ingredients of the same purity, chemical inertness, concentrations, or sound and sturdy construction. For this reason, materials are tested annually or upon each formulation or supplier change. For materials which are manufactured in a variety of colours, such as papers and inks, each colour is evaluated and reported separately.

ISO 18922:2002 is applicable to evaluating the scratch resistance of dry, processed photographic film. It specifies two test methods for evaluating the scratch resistance on either the emulsion or the base side. The two test methods usually give comparable results. It provides empirical laboratory tests made under controlled conditions, but does not necessarily predict the actual scratch resistance of a film in any particular commercial machine. Method A gives a measure of the minimum load requirement to produce a scratch, requires less elaborate evaluation equipment and is less stringent in its requirements of the optical condition of the specimens. Method B provides a measurement of haze produced by various stylus loads, is a more complete measure of scratch characteristics of a material and is the preferred method.

ISO 18905:2002 establishes specifications for the stability of polyester-base safety film which has an ammonia-processed diazo photographic image. It is applicable only to diazo photographic films intended for and used as LE-10 and LE-100 storage copies, which shall be stored in accordance with ISO 18902 and ISO 18911. ISO 18905:2002 is applicable to photographic film in which the image layer is a discrete layer attached to a transparent support, and it applies to roll film and sheet film. ISO 18905:2002 is not applicable to diazo film records intended and used as work copies.

ISO 18912:2002 establishes specifications for the stability of polyester-base safety film which has a heat-processed vesicular photographic image formed by nitrogen bubbles. It is applicable only to vesicular photographic film intended and used as LE-10 and LE-100 storage copies, which shall be stored in accordance with ISO 18902 and ISO 18911. ISO 18912:2002 is applicable to photographic film in which the image layer is a discrete layer attached to a transparent support, and it applies to roll film and sheet film. ISO 18912:2002 is not applicable to vesicular film records intended and used as work copies.

ISO 18903:2002 specifies a method for determining the dimensional change of photographic films and papers caused by: variations in equilibrium moisture content due to change in the relative humidity (RH) of the atmosphere (humidity coefficient of expansion); change in temperature (thermal coefficient of expansion); processing; ageing. ISO 18903:2002 deals with the moisture content and thermal history of the specimens before measurement, the atmospheric conditions during measurement, and the treatment of the data. It does not describe the various experimental techniques used to make the measurements. This International Standard is not suitable for determining the dimensional change of instant photographic film.

This Technical Report discusses devices in photographic standardization that are used as hygrometers and humidistats in the measurement and control of relative humidity (RH) in test chambers and storage areas. Special attention is given to situations where a photographic standard specifies controlling relative humidity to _ 2 % RH or better. Electric hygrometers are recommended for their precision, low cost, and accuracy when properly calibrated. Calibration can be done either by the vendor or in-house by a dew-point measurement. Where the budget permits, dew-point combined with ambient temperature measurements (converted to relative humidity) may be the only sensor system.

This International Standard provides specifications and test procedures for establishing the safety of photographic films with respect to hazards from fire. The specifications are applicable to both unprocessed and processed1) films on any type of currently known plastic support. These specifications cover silver films (both gelatin and non-gelatin types), colour films, diazo films, vesicular films, and striped or full-width magnetic films. Magnetic tapes and video recording tapes are excluded. A field test for burning behaviour is described in informative annex B, and methods of marking film are defined in informative annex C. A simple test to distinguish non-safety nitrate-base film from cellulose ester and polyesterbase film is given in informative annex D.

1.1 This International Standard describes methods for evaluating the effectiveness of chemical conversion treatments intended to increase the resistance of wet-processed silver images to oxidation. The treatment may be applied as part of the original processing, or it may be a post-processing treatment. This International Standard does not recommend general or specific treatments for silver images. Likewise, treatment temperature, times and replenishment rates are outside the scope of this International Standard. Factors to be considered in a stabilizing treatment are discussed in informative annex B. Two test methods are described: the "dichromate bleach test" and the "hydrogen peroxide incubation test" (see [7] in the bibliography). The significance of each is discussed in informative annex C. 1.2 This International Standard is applicable to silver-gelatin images coated on supports of either plastic, paper or glass.

This International Standard provides recommendations concerning the storage conditions, storage facilities, enclosures, and inspection for recorded polyester-base magnetic tapes in roll form. It covers analog and digital tape and includes tape made for audio, video, instrumentation and computer use. This International Standard is applicable to medium-term and extended-term storage of magnetic tape as defined in 3.18 and 3.7 and also is applicable to magnetic-tape records intended as master tapes, which should not be in frequent use. Deviations from these recommendations, whether before or after recording, may result in shortened life expectancy. For example, adverse conditions during shipment, handling, or usage. This International Standard is not applicable to "work" or "use" copies (see informative annex C).

This International Standard specifies methods for determining and quantitatively expressing the curl characteristics of unprocessed and processed photographic film and paper in sheet, roll or strip formats. It specifies three measuring methods: method A involves the determination of curl when the specimen is held in a vertical position, methods B and C with the specimen in a horizontal position. The values for the three methods are not comparable because of the differences in specimen configuration and size. These methods are not intended for use in determining the curl characteristics of photographic materials during processing or drying.

This International Standard specifies a method of determining the presence of a lubricant on photographic film. It is intended that the test should be applied to film after processing, but the test may be used in other situations. It is applicable to both the emulsion and support sides of the film. The results of the test are calculated in terms of a coefficient of friction, but the test does not purport to characterize the frictional characteristics of the film material.

This International Standard specifies a method for determining and quantitatively expressing the folding endurance of photographic film. The method is based on the MIT folding-endurance tester described in annex B. It is an analytical test and is not intended to simulate practical use conditions. This International Standard is applicable to film with or without a gelatin backing. It may also be applied to either raw or processed film, although the flexibility level of a given film can be quite different after processing. Equipment similar to that described in this International Standard may be used provided that a correlation has been established between the results obtained using such equipment and the results obtained using the equipment described.

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.

This International Standard establishes specifications for the stability of photographic films intended for storage of records; specifically, microfilms with a base of safety polyester [poly(ethylene terephthalate)] having predominantly silver behenate salts dispersed in nongelatinous emulsions, and thermally processed to produce a black-and-white silver image. This International Standard applies to thermally processed silver (TPS) microfilms having ultrasonic or dielectric (induction-heated) splices. It does not cover films with splices made by means of adhesive tape. This International Standard does not cover other types of black-and-white TPS films, black-and-white paper, colour images and colour prints that are produced with thermally processed silver behenate systems. It does not apply to films to which lacquers have been applied. It also does not apply to conventional black-and-white silver images that are produced by wet processing of silvergelatin films (see ISO 10602).

1.1 This International Standard specifies test methods for the determination of residual thiosulfate and other related chemicals in processed photographic materials. 1.2 This International Standard applies to silver halide/gelatin products that have been processed with a final thiosulfate fixing bath and a water wash. This International Standard does not apply to stabilised black-and-white products, thermally processed films, or instant-type products. The procedures given in this International Standard measure residual thiosulfate, and the silver densitometric method measures residual related polythionate materials as well. Measurements carried out by the procedures in this International Standard may, within the limitations stated in annexes A and B, correlate with the image stabilities of processed photographs. 1.3 Film or plates with photographic-sensitive layers on both sides, or with a photographic sensitive layer on one side and a gelatin backing layer on the reverse side, may contain approximately twice as much thiosulfate after processing as samples having a coating on one side only. This situation will be true for materials for which residual thiosulfate is determined by the iodine-amylose or methylene blue procedures. NOTE For the method of reporting such results, see figure 1, example 2. 1.4 The iodine-amylose can be used with fibre-based paper, resin-coated paper, films and plates. It is the method to be used with films and papers containing incorporated developing agents. 1.5 The methylene blue method can be used with fibre-based paper, resin-coated paper, films and plates but not with films and paper containing incorporated developing agents. 1.6 The silver sulfide densitometric method measures thiosulfates, polythionates and all other residual chemicals in a processed product that react with silver ion to form a silver "stain" under the conditions of the test. 1.7 A tabulated summary of methods, scope, etc. is given in annex B.