Volume 25, Number 5
Feb 2002

ANSI/ISO Update for Permanence and Physical Properties of Imaging Materials; Pt. 1

The following update is from the ANSI IT9/ISO TC42 (WG 5) fall meeting in Fort Lauderdale, Florida, it is a discussion of new issues. A list of the most recent versions of standards of potential interest and their status, will appear in the next issue of this newsletter.

What's New

Three new major topics came-up at the meeting dealing with digital images: mounting/matting/framing/coating of prints, and the handling of magnetic tape.

I. Stability of digital prints.

There has been significant interest in this area and an ANSI sub-committee, IT9-3, the third sub-committee of IT9, has been given responsible for the permanence of a variety of prints. This is the largest group with over 40 members; it's larger than the parent committee.

This area is relatively new and encompasses a wide variety of materials. Issues and terminology are very complex and it is often difficult to reach a consensus. The committee started out as a color photographic group dealing with conventional photographs including chromogenic, silver dye bleach (Ilfochrome), dye diffusion (Polaroid), and dye imbibition (dye transfer.) It is now focussing on what were once known as "digital hardcopy" (ink jet, dye sublimation, thermal wax, electrophotographic, etc.) Of course chromogenic and silver dye bleach prints can also be created from a digital file (and they are both hardcopy objects by definition.) It is therefore difficult to create a term that encompasses the wide range of modern printing methods, but that excludes traditional photographs. There has also been objection to the terms "media" and "materials" within the committee. Furthermore, the scope can't be limited to color because monochrome ink jet images are included. It has been proposed that anything that looks like a photograph should be called a photograph (including ink jet), but not everyone agrees. At one time, the sub-committee considered a photograph to be images that were at one time light sensitive. Even then there was concern because this definition excluded peel-apart Polaroid prints and dye transfers. Clearly, it is difficult to create appropriate terms let alone test methods and requirements.

The sub-committee, IT9-3 is so large that it has broken into seven task groups to deal with various issues:

Humidity fastness deals with the potential problem of bleed, migration, spread, and transfer of the image under high humidity conditions.

Water fastness deals with the problem of image damage including complete solubilization, bleed, transfer, and surface change (such as gloss) when a print either gets wet and is left to dry or gets wet and is wiped or blotted.

Fingerprints deals with the problem of fingerprints affecting either the printability of a substrate or the subsequent disfigurement of the image during long-term storage or display.

Indoor light stability deals purely with light stability under fluorescent and simulated daylight exposure.

Outdoor weathering deals with images that are intended for use outdoors; primarily for commercial purposes.

Dark stability deals with the stability of images that are stored in the dark. Only the effects of temperature and relative humidity are addressed here.

Gas fading and moving air exposure deals with the effects of both atmospheric pollutants and exposure to clean moving air. This area has been identified as very import to both light fade testing and dark stability for many modern, non-traditional imaging materials.

One of the most significant results of the meeting was recognition that public education is needed. Decades of experience with conventional color photographic processes led to the industry-wide belief that stability for consumers was dictated almost exclusively by light stability and this is the message that consumers received as a result. As significant stability issues have been identified the industry has come to realize that the life of an image was much more complex. A single number would no longer answer the consumer question, "how long will this last?" It was agreed at the meeting that it would be misleading and a disservice to consumers if they were not educated to look at more than one factor when judging the expected stability of an imaging system. In particular, it came as a surprise to the industry that some images are quite sensitive to atmospheric pollutants such as ozone. Even more surprising was the further discovery that some images will fade quite rapidly even in clean moving air. In either case, it is critical that the images be framed. Unfortunately, it has also been recognized that modern images are most commonly displayed on refrigerators without any protection at all. For the standards committee and the industry, the impact of air and atmospheric pollutants is significant enough that it can cause drastic differences between predicted life-expectancies based on accelerated light and dark stability tests and the results of real-life storage or display. Clearly there is no longer an easy answer to the question, "how long will this last?"

II. Finishing of prints including matting, mounting, framing, and coating.

The group dealing with image processing turned over performance standard for pressure sensitive adhesives and dry mounting tissues to the permanence group since both standards really deal with post-processing activities. The two standards being reviewed are American National standard for Photography (Processing) – Pressure-Sensitive Adhesive Systems for Use in Mounting Photographs – Specifications, ANSI/PIMA IT4.20-1998 and American National Standard for Photography – Thermally Activated Adhesive Dry Mounting Systems for Mounting Photographs – Specifications, ANSI/PIMA IT4.21-1997.

The sub-committee is working towards updating the two standards to include permanence issues relating to the effects of the adhesive (and carrier where applicable) on the mounted photograph and to convert the updated documents to ISO standards. Currently there are no parallel ISO documents. In addition, the sub-committee is hoping to produce a standard for mounting, framing, matting, and coating of prints. Currently coating is focussing on spray lacquers and UV cured coatings such as Scotchguard (formerly known as Photoguard.) There are several people from the photo conservation community who have been recruited for help (all are member of the sub-committee). The manufacturers will also be invited to add their perspective. Seal and 3M, among others, were involved in the creation of the original adhesive standards cited above.

III. Care and handling of magnetic tape

The joint technical commission responsible for electronic media (magnetic tape and optical disc), consisting of members of ANSI sub-committee IT9-5 and member of the Audio Engineering Society, is working on a standard dealing with the care and handling of magnetic tape. Functionally this is a companion to ISO 18923 which deals with the storage of polyester base magnetic tape. Tentatively, the document will deal with handling techniques, handling environments (potentially different from storage environments), use, cleaning, maintenance, transportation, disasters, training, and archival issues. This document is still in the early stages of development and hasn't reached a committee draft (CD) yet. The standard number reserved for this publication is tentatively ISO 18933. People dealing with magnetic tape in collections should know that these important issues are being addressed at this time, even though a standard may take several years to produce.

(Continued in next issue)