[Digital BW] Jon Cone's perspective on PiezoTone stability
2002-06-15 by Paul Roark
Antonis wrote: >Jon has asked me to upload his fade test image and some comments he >wrote regarding Paul Roark's test of the Black ink only. I wonder if Jon would allow the fade test I did to be posted on his forum or even discussed on his forum. The reason I abandoned that forum is that he refused to allow any such discussions. >You can find these at: http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/ >... look under Ink Sets. It will >be obvious where the PiezoTone section is. Here is Jon's statement: >Jon Cone asked that the 100 hour Xenon Arc tests of the full ink tests be >placed in comparison to the Paul Roarke tests. Jon Cone felt that the >example of a black ink only test is misleading because neither product is >designed to be printed with black ink only. I have been very clear about this being a black-ink-only test. The black ink, however, is critical. Obviously, fading will cause shadow density decreases and lowering of contrast/flattening in the shadows. Perhaps even more important, the warming of the black ink may cause a very visible warm tone cross-over in the shadows. >A 50% patch of black is not printed with either the PiezographyBW >Workflow, or the RGB Curves workflow, or RGB EPSON output. Black ink >is only >printed in the very high 80% range and in minute quantity with Piezography >and is not present until the 90% range in strength. This is similar but not >exactly how the EPSON driver prints black in terms of densities present. And >of course there are other inks under this black ink that are essential to an >evaluation of meaningful data. The only way to tell exactly where the black ink starts in the Piezo driver is to load a cleaning cart in the color ink position and see where the ink starts. In the Epson driver the black ink is gradually fed in perhaps as high as the 65% patch, but I really have never done this experiment. I would think it would be very unusual to have an abrupt change in the ink. It would almost certainly leave an artifact. >PiezoTone inks do not use dyes in the non-black position inks (cyan, photo >cyan, magenta photo magenta, yellow) Which implies and he later states, consistent with my test, that they do use dye in the black position. Yet, in Message 18880, dated June 10, on the Piezo 3000 forum Jon Cone stated: "The inks do not use dye stuff ...." > and which is why there is no warm >fading with prints made with PiezoTone inks. The addition of dyes in black inks appears to be what causes those inks to warm more than straight pigment inks. Warming of the black ink is not just a pigment problem. > MIS-FS inks use a different >formula which may or may not contain dye in them, but do warm considerably >in comparison to the PiezoTone inks. As far as I am aware, the MIS FS inks do not use dyes. They are a straight and simple dilution of the VM/FS black. >PiezoTone black uses a trace amount of dye because carbon itself is not >black enough to get a high dMax. How much dye? I think Generations is honest about their black having 25% dye. I call that more than a "trace." Look, the reason I was interested in the black ink is that, as far as I know, the only way with currently-available technology to get a black better than the VM/FS black is to add dye. The blacker the ink beyond this point, the more dye has been added. If some one had found a pure pigment that offers a better black or longer life, then I'm interested. Otherwise, I'd like to know what the trade-offs are. > It is the only position which has dye >content. Its warming will not be noticeable in conventional use such as >PiezographyBW software, RGB Curves workflows, or RGB EPSON driver output. Well, time will tell. People have commented on the shadow warm shift in inksets with less of a problem than I expect PiezoTones will have. >These test images clearly shows that a typical full range image printed with >PiezoTone inks does not warm fade as the MIS-FS inks do. The black ink only >test implies the opposite. For these tests, the center of a print was cut >out and exposed to 100 hours in a Xenon Arc chamber, then taped back into >the print from the rear, which accounts for the rectangular shapes within >each image. At some point I'll probably test the full PiezoTone inkset. However, I'm not really interested in getting into an extended debate on this subject. I was interested in the black ink, and I do hope that the Piezo users don't have serious unexpected problems. But, frankly, that is not my problem. (Although I would hate to see the entire quad inkjet industry get a bad reputation.) I also am not a big fan of standard FS inks. When I print warm, I print very warm -- the sepia (actually light sepia curve) end of the MIS VM-Sepia inkset. I like the FS-Neutral inks, which are the gray inks in the VM-S inkset and were the first non-warming formula available, as far as I know. I'll probably, in fact, test the FS-N inks at the same time as the PiezoTone inks to see how they compare. I hope some others test these inks in different conditions. I also would recommend that some Piezo users try the Piezo midtones with Generations Enhanced K. I think it is cheaper and warms less. Frankly, I thought that was what the PiezoTone K probably was. I was shocked at the performance of the new PiezoTone black. Paul http://www.PaulRoark.com