BS ISO 18920:2011 pdf free download Imaging materials — Reflection prints — Storage practices
4Enclosures and containers
All enclosures and containers used for medium-term and extended-term storage shall meet the requirementsof lS 18902 and ISO 18916.This includes enclosures and containers that are in either direct or indirectcontact with the prints.Prints may be stored in envelopes or sleeves of paper or plastic, file folders, foldingcartons, boxes and albums,or may be matted.Prints shall be protected from unnecessary use and lightexposure.Prints that are prone to light-induced fading, especially diazo and some colour processes, shall notbe exposed at all.
Generally, prints smaller than 28 cm × 36 cm in size may be stored vertically, but shall be placed between rigidsupports to minimize slumping and curling.Prints 28 cm × 36 cm or larger should be stored horizontally, unlessmounted on rigid supports.Stacks of horizontal prints should be less than 5 cm high to prevent excessivepressure on prints at the bottom.
Multiple prints, stored within an enclosure or container, shall be oriented with the emulsion sides against backsides, never emulsion against emulsion.
Suitable plastic enclosure materials are uncoated polyester (polyethylene terephthalate), polystyrene, high-density polyethylene and polypropylene.Other plastics may be satisfactory, but there has been no extendedexperience with such materials. Glassine envelopes and chlorinated, nitrated, or highly plasticized sheetingshall be avoided.Specifically,cellulose nitrate and polyvinyl chloride are not acceptable.Glassine is notdimensionally stable when exposed to high relative humidity, although it may meet the other requirementsspecified in lSo 18902 and pass the photographic activity test.
Microclimates (sealed enclosures or cabinetry) shall be used where needed in order to maintain the desiredmoisture content of the prints where humidity control is inadequate in storage rooms or where cold storage vaultsand units do not have humidity control, and to protect against gaseous and solid atmospheric contaminants.A variety of sealed vapour-proof housings, containers and cabinetry can provide this protection (as discussedin Table 1,7.1.3.2 and Annex H).
The adhesive used for seams and joints shall also meet the requirements of lSO 18902 and ISo 18916.Thefiling enclosure shall be constructed so that the seam or joint will be at the edge of the enclosure and not incontact with the image layer. Photographic-quality gelatine, modified and photographically inert starch, someacrylic and polyvinyl acetate adhesives and methyl cellulose are suitable adhesives for use with paper.
For maximum life,prints shall be in a clean condition before being placed in storage and shall be inspectedperiodically thereafter, as outlined in 9.3.
5 Storage housings
Prints shall be stored in closable storage housings such as drawers or cabinets, in storage cabinets with tightlyfitting doors, or on open shelves when enclosed inside containers. The storage-housing materials shall benon-combustible,non-corrosive,and chemically inert, e.g. anodized aluminium, stainless steel or steel witha non-plasticized synthetic resin-powder coating. Wood, pressboard, particle-board, plywood and other suchmaterials shall be avoided because of their combustible nature and the possibility of their producing activedeteriorating agents as they age.
The finish on the storage housing materials shall be durable and shall not contain substances that can have adeleterious effect on the stored prints. Finishes containing chlorinated or highly plasticized resins, or solvents giving off gas from freshly applied finishes can adversely affect the image and base layers on prints.Paints usedon cabinets may give off peroxides, solvents and other contaminants for up to three months after application.Cabinets made of stainless steel or anodized aluminium are recommended.Metal housing materials that havebeen powder-coated (a layer of resin particles that are applied electro-statically to the surface of the metal andthen fused to the surface using heat without the use of chemical solvents) are also recommended.
When air-conditioned individually, storage housings shall be arranged to permit interior circulation of air to allshelves and drawers holding print containers, so as to provide uniform humidity conditions. Storage housinglocated in rooms conditioned in accordance with 7.1 shall be provided with ventilation openings that permitaccess of air to the interior. Such openings shall not interfere with the requirements for fire-protective storageor water protection.
Different types of prints , films and other media may be stored in the same storage room separately from each other.However, different types of material shall not be stored (interfiled) within the same enclosure or storage container.
6 Storage rooms
6.1 Medium-term storage rooms
Rooms and areas used for print storage should be located in the same area as rooms containing provisions forinspection and viewing of prints. Good housekeeping is essential. Walls and enclosed air-conditioned spacesshall be designed to prevent condensation of moisture on interior surfaces and within walls,especially duringperiods of low exterior temperatures when the walls may be cooled below the dew point of the air.
Provisions shall be made against damage of prints by fire and by water from floods, leaks and sprinklers, and fromthe steam released from masonry walls during a fire[7][9][12][17)].Storage rooms or vaults should be located abovebasement levels where possible. A special storage room separated from the work areas for prints of medium-term interest generally will not be required, provided the conditions recommended in 7.1.2 are maintained.
6.2 Extended-term storage rooms
For extended-term storage, the requirements of 6.1 shall be met.
In addition, the value of photographic prints kept for long-term purposes makes it advisable to provide a storageroom or vault separate from medium-term storage facilities, temporary storage facilities, offices or work areas.
7 Environmental conditions
7.1 Temperature and humidity specifications for storage
7.1.1General
See Annexes A,B,C, H and l.
The recommended temperature and relative humidity conditions in Table 1 shall be maintained either withinindividual storage housings or within rooms containing such housings.