Indelible Black Ink Fade Test
2002-03-02 by Paul Roark
I have posted the results of a fade test in the Files section of this forum. The Files section is at: http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/ Then go to "Inksets, reviews and techniques" and see the "Indelible v MIS VM K 300Hr Fade.jpg." The short summary is that the Indelible black ink test strip faded and warm-shifted much more than the comparison MIS VM/FS black ink test strip. (A description of the procedures and detailed results are below.) Because I'm interested in longevity and resistance to warm-shifting, my tests have been limited to pigmented inks (although some claim that all of the desktop "pigmented" inks have some dye in them -- I don't know). Compared to this sample, the Indelible black ink mid-tones exhibited the worst warm-shifting I've seen. At 15.4 units, it's about twice the 8 units I expect, on average, from pigmented inksets, and more than 3 times the MIS VM comparison test strip warming, at 4.4 units, as measured by my scanner. I, unfortunately, did not have a Generations Enhance black ink test strip in the fader at the same time. I think this would be the most comparable ink to test and compare the Indelible black ink to. Media Street is up-front about it's Enhanced black having about 25% dye in it. I would guess that Indelible black also has a significant dye component, based on what I see in the fade test results and the depth of black and tone of the ink when first printed. I used the MIS VM black ink as a comparison. Thus, in the florescent light fader along with the Indelible black ink test strip was a test strip printed with MIS VM black ink. (This is the same as the MIS FS black ink, and probably the same as Piezo black ink.) Both prints were on Epson Archival Matte paper, printed at the same time, and allowed to dry overnight before the test started. The test strips were rotated in the fader to eliminate any chance of uneven light (which I've never detected anyway). After 300 hours in the fader, the test strips were measured by both an Epson 1600 Expression scanner and an X-Rite Digital Swatchbook spectrophotometer. With the scanner, I select a relatively large portion of the test patch and then use the Photoshop Histogram tool. The relative changes in the test strips were consistent between these methods and consistent with the visual impression. At the 100% black patch of the 21-step test strip, my primary interest is the visual fade. The scanner black point setting, of course, controls the absolute numbers, but the change in these numbers between the control (dark storage) strip and the test strip should show the relative amount of fade. Indelible 100% K control = 7.23, 300 hour test strip = 10.93; Relative fade (change in luminance) = 3.7. MIS VM 100% K control = 13.61, 300 hour test strip = 14.55; Relative fade (change in luminance) = 0.94. X-Rite visual density readings: (Where my 3 readings were not identical, I add a + or - to indicate the direction of the higher or lower reading.) Indelible 100% K control = 1.76, 300 hour test strip = 1.71-; Fade (change in visual density) = 0.05+. MIS VM 100% K control = 1.67, 300 hour test strip = 1.66; Fade (change in visual density) = 0.01. Outside the 100% black, both fading and warm-shifting become important to me. I measure warming as the change in the Red-minus-Blue values, as read by the scanner. With black-ink-only printing, the "70%" patch of the test strip is about the same density as the 50% patch of a Piezo or MIS VM quad 21-step test file print. Thus, I measured the 70% patch of the control and test strips as representative of the midtone fade and warm-shift characteristics of the inks. Scanner results: Indelible 70% fading (change in scanner luminance values) = 4.9. Indelible 70% warming (change in R-B channels) = 15.4. MIS VM 70% fading (change in scanner luminance values) = 2.86. MIS VM 70% warming (change in R-B channels) = 4.4. X-Rite results at 70% patch: (Density read-out order is cyan, magenta, yellow, visual.) Indelible 70% control = 0.68, 0.65, 0.66-, 0.67-. Indelible 70% 300 hour = 0.58, 0.61, 0.65, 0.60. MIS VM 70% control = 0.58, 0.58, 0.59-, 0.58, MIS VM 70% 300 hour = 0.55, 0.56, 0.58, 0.55. (Note that the Indelible ink sample for this test was from a third-party user and tester. I now also have a sample from a party involved in the distribution of the ink. The next time I test the ink, I will use this new sample and compare the ink to Generations Enhanced black. However, such test may be delayed for some time due to other priorities. The current fade test was stopped at 300 hours.) Paul http://www.PaulRoark.com