The 20 Megalux-hour light fade test results for the first twenty samples in test are now available. Twenty Megalux-hours of accumulated light exposure is equivalent to ten years on display using the industry-standard extrapolated display lighting conditions of 450 Lux for 12 hours per day. The test sample summary page and PDF reports for all 20 samples can now be accessed from the AaI&A Digital Print Research page.
As I have noted in previous posts, the 20 print samples now in test were all made with pigmented ink systems. Most of the samples remain in outstanding condition as we would hope for and also expect of pigmented-ink prints. However, measurable albeit very small changes in some instances have been recorded by the instrumentation for all samples. Additionally, significant fading has already occurred with two test samples (AaI_20071008_SN002 and AaI_20071008_SN007). They were printed with a third party ink installed in an Epson R1800 printer. Compare these samples to the samples printed with Epson OEM R800/R1800 ink on the same papers (AaI_20071008_SN013 and AaI_20071008_SN018). Also, note that the choice between the two paper types has influenced the third party ink fading resistance by at least a 2x factor so far. I draw your attention to these results not to make sweeping generalizations about third party ink sets (which I believe serve a useful role in the marketplace), rather to underscore an important point about AaI&A light fade testing. Current industry practice is to simplify consumer information by reporting “when” but not “how” a product fades. In contrast, the AaI&A test results indicate when the product is fading, how it is fading, and to what extent it is fading over time.
One can already conclude that the yellow ink plays a key role in the light fastness properties of the R800/R1800 Ultrachrome Equivalent ink set from MIS Associates (www.inksupply.com). Images printed on the two papers in test are retaining excellent visual contrast after 20 Megalux-hours of light exposure but not good color balance. The tests predict that color balance will shift noticeably towards blue within 10 years on display at an average 450 Lux for 12 hours per day, particularly for images with large areas of low to moderate chroma such as neutral or near neutral gray colors as well as skin tones. If the manufacturer works to improve just the stability of the yellow colorant in this ink set, retained color accuracy over time will significantly improve on these two papers and probably others as well. Likewise, knowing that the yellow ink is the weak link provides the end-user of this third party ink set with some potentially interesting options. For example, substituting the third party yellow ink with the OEM yellow ink and thus creating a “hybrid” ink set might very well boost the light fastness while preserving approximately 6/7ths of the CIS ink cost savings (the R1800 uses 7 individual inks). Or the end-user could try substituting another bulk yellow ink into the continuous ink supply (CIS) system often used along with third party inks. These options are logical only if one knows that one ink, in this case yellow, is fading significantly faster than the other inks, and the outcome can only be confirmed with further testing. The AaI&A light fade testing program thus offers a good opportunity for its membership to collectively assess unique combinations of materials.
By contributing actual print samples to the AaI&A light fastness testing program, AaI&A members have a strong voice in what products get tested. Printmakers are clearly experimenting today with ink sets, overcoats, and “mix and match” material combinations. One of our goals at AaI&A is simply to conduct image permanence research and standardized testing on the printing technologies our members elect to use. With a little foresight and luck, these systems and their test results will add a rich significance to the history of digital printing and photography.