The Photographic Activity Test (PAT) is a worldwide standard (ISO Standard 14523) for archival quality in photographic enclosures. Developed by IPI ( Image Permanence Institute), this test predicts possible interactions between photographic images and the enclosures in which they are stored. The PAT is also used to test the components of enclosures, such as adhesives, inks, paints, labels, and tapes. The test involves incubating materials in temperature- and humidity-controlled chambers to simulate aging and takes from four to six weeks. After incubation and sample evaluation, a final report is provided. It is the subject of International Standards Organization standard 14523:1999 subsection (E) Photography-Processed photographic materials-photographic activity test for enclosure materials.

Samples of the enclosure material to be tested are stacked into a "sandwich," along with special degradation detectors, and various other materials necessary for the test. All of these materials are held together in a stainless steel jig. A second control sandwich is prepared using a known good enclosure material.

Samples are then incubated for 15 days in a temperature- and humidity-controlled chamber at 70°C, 86% RH. If the detectors that have been incubated with the test enclosures are more faded or much less faded or are more stained than those incubated with the controls, then the enclosure material fails the test.

Instruments are used to measure fading and staining. The pass/fail limits have been derived from enclosures that are known to have caused fading or staining in real-life storage situations.

Clear File Inc. ArchivalPLUS and ArchivalCLASSIC PAT Test Results.

Independent laboratory tests prove that Clear File archival storage pages provide safe, long-term protection for negatives, transparencies and prints.

Clear File uses a specially formulated polyethylene and polypropylene so that their products provide maximum long term protection for delicate photographic emulsions. Clear File's museum quality, archival pages are acid free (pH Neutral) and contain none of the platicizers, catalysts or solvents found in PVC.