Dark stability of printed ink jet media for specified periods of time is pertinent to the end use of these materials. While natural aging is the most reliable method of assessing image stability, the length of time required makes this practice impractical for most materials. As a result, accelerated tests often are used. This practice is an accelerated short-term storage practice that simulates long-term storage but at elevated temperature. It provides faster results and is intended to identify problems that may occur over extended time periods. A room condition sample also is tracked to provide practical data. Because testing is done at a single set of conditions, it is not intended to be a long-term predictor as achieved through Arrhenius testing.

Note 2—The results from single accelerated tests can lead to inaccurate results. This procedure should be used only for early-screening information in side-by-side comparisons only. Arrhenius testing, which is based on mathematical extrapolation of a series of high temperature tests to room temperature, is a better predictor of a product’stability.⁵

5.1.1 Since the ability of an ink jet print to withstand color changes is a function of temperature and humidity, it is important that dark stability be assessed under the conditions appropriate to the end use application. While ink jet prints may be handled and displayed under a variety of conditions, this test practice is intended to produce the color changes that may occur in ink jet prints upon dark exposure in typical office environments.

5.1.2 The accelerated procedure described in this test practice is intended to provide a means for the rapid evaluation of dark stability under laboratory conditions. Test results are useful for specification acceptance between producer and user, for quality control, and for research and product development.

5.1.3 Color changes are not a linear function of duration of incubation. The preferred method of determining dark stability is to incubate the prints for a number of intervals, and to assess the exposure time required to obtain a specific color difference.

1.1 This practice describes an accelerated procedure intended to determine the dark stability of ink jet prints.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.