Validity of Dark Storage Test Method

Abstract

The dark storage test relies on elevated temperatures to accelerate aging of print materials that are kept in photo albums, file cabinets, shoe boxes and other enclosed containers. However, the widely used free hanging test method in dark storage testing of print images does not simulate the actual consumer storage condition. Few studies have been performed to check the validity of the accelerated thermal test for print images because the accelerated tests themselves can take months or years to complete. Earlier research into the sources of noise in the dark storage test found that porous photo papers exposed to ozone prior to starting the accelerated thermal test would fail much faster. By deliberately pre-conditioning porous photo papers with ozone it is possible to accelerate these media thermal tests by orders of magnitude. This makes it possible to finally compare ambient real world dark storage test results to testing at elevated temperatures. This paper will describe those observations, which include some unexpected but repeatable results.