Fade Test -- New inksets
2004-07-19 by Paul Roark
I'm just back from Golden Trout High Sierra Camp, and an important fade test has reached the 600 hour point where I think I can draw some interesting information. It's almost all very good news for B&W printing with inkjets. Here are some highlights. All test strips were on Epson Enhanced Matte paper. I'm using the X-Rite Lab readings to summarize some of the potentially important results. I separate the lightness changes (Delta L) from the chromaticity (hue shift) changes (which I'll call Delta E [Error] here). I think we understand that our images will probably slowly move in hue toward the base warm carbon tone. However, I've very interested in having the base warm carbon image not fade (become lighter) to the maximum extent possible. So, I think the separated "fade" and color shift results are more informative than a combined total Delta E. (Delta E for chromaticity is the standard Pythagorean theorem distance between starting and ending (a,b) points.) For now I'm looking at the 50% midtones only. 1. UT2 with neutral curve. This was arguably the best neutral ink I've tested. So, it's worth using as a standard for now. (UT-FSN would be about the same.) L (lightness, with 100 being white) went from 57.46 to 57.70. So, it lightened or faded about 0.4%. Delta E = 2.7 2. UT2 with carbon curve. The carbon image is what I consider the most stable, at least in terms of visual density fading. We know that it will yellow a bit. L went from 56.85 to 56.76. It actually darkened a bit (about 0.16%). Delta E = 2.2 3. 7500 6-04 (first UT-8 beta (new blue toner)), neutral curve. I loaded my 7500 with a new UT1 toner that is composed predominantly of a new UT-family blue ink from MIS. (Not publicly available, as far as I know.) I think this toner approach will be appear in UT-8 for the 4000. L went from 56.58 to 56.46. It darkened a bit (about 0.2%). This is the first neutral ink that I've tested to make it into the same class with Eboni and carbon UT in that is actually darkens a bit in my 600 hour test. This is very good news. Delta E = 2.5. This overall number hides the more important result that the loss of magenta (green shift) is much lower than UT2-N and very close to the carbon shift. 4. UltraChrome-VT with the Carbon curve L went from 56.41 to 56.73. So, it fades a bit (about 0.5%) and does not darken the way the MIS carbon inks do. Delta E = 2.5 5. UC-VT with neutral curve L went from 57.19 to 57.83. So, it faded a bit more than 1%. Delta E = 2.8 This may not seem great, but this result is good and indicates the new base (glycerol + distilled water) is working. 6. UC-VT, neutral curve, PremierArt spray. L went from 53.47 to 53.93. So, it lightened about 0.8%. Delta E = 1.8. Wow, a new champ of color stability. This PremierArt spray, as in other tests I've done, makes a major change in UltraChrome stability. (The B72 spray was not in the same class. The changes for MIS inks with the PremierArt spray are more on the order of a 10% improvement as opposed to this UC 35% improvement.) This is very significant. Ink mixers now have the UC inks as a base to make excellent B&W inksets that have the coated Epson pigments and any other attributes people may think Epson inks may have. I'll publish the first draft formula for this totally off-the-shelf inkset. I will stay with MIS inks for UT-8, however. I like the superior carbon stability. It's good and getting better. 7. IB-FS L went from 62.95 to 62.91. So, it darkened just a hair. Delta E = 2.5 This is my first inkset to use a toner pigment from outside the inkjet field. It uses a blue pigment that, by itself, offsets the carbon tone to make a more neutral (slightly "selenium") print. I used the MIS UT base, so it sticks on glossy paper. This is not ready for the next generation, but it demonstrates several important things. First, we're not stuck with the inkjet field pigments. It's a much larger world out there. Second, with this variety of pigments available all sorts of potential new systems become possible. This ink, for example, could be the blue end of a hybrid Lab-space inkset that acted to neutralize the carbon. The standard CMY could be overlaid, or the creative might want to go to red-green Lab a axis. I also see this merging with water color art. Fun stuff. Paul www.PaulRoark.com <http://www.paulroark.com/> [Non-text portions of this message have been removed]