If longevity of color prints is also considered then third party color inks still have to improve compared to the HP Vivera pigment ink.
Actually, so could Epson and Canon OEM ink sets aspire to be as good as the HP Vivera pigments.
HP has achieved a terrific yellow lightfastness which in turn reduces overall color shift over time, and while there may be some technical arguments regarding color constancy, gamut, etc., that caused Epson and Canon to go with one yellow pigment type whereas HP went with another, in practice all three OEM sets deliver excellent initial color quality. The achilles heel for both Epson and to a somewhat lesser degree for Canon is primarily the yellow pigment. If Dano or anyone else at Epson is reading this thread, how about considering the idea of offering an alternative yellow ink for folks that really do care about print permanence? If any third party vendors are reading, I also humbly suggest you have an opening by targeting an improved yellow pigment ink for Epson Ultrachrome printers.
Unfortunately, at this time nearly all third party inks I have tested to date have an even weaker yellow than the Epson Ultrachrome yellow and none have a more lightfast yellow which is not good considering yellow is already the weak link in the Ultrachrome lightfastness chain. Some popular third party pigmented ink sets (e.g., ConeColor Pro) have a weak magenta pigment as well which is arguably more problematic than a weak yellow.
Canon Lucia inks could use some modest improvement in both yellow and the red(orange) inks as well as the green ink to bring up total performance to HP levels but that said, the Lucia skin tone blend light fade performance still outperforms the Ultrachrome skin tone blend lightfade performance by a significant margin. One cannot overstate how important yellow ink lightfastness is for color blends like skin tones. It should go without saying that skin tones are an especially important subset of printable colors considering how many photographs are portraits of people. The very first fading problem people spot in many limited edition litho prints is loss of yellow and a consequent "purplish-blue" color shift in the print. Most litho prints are made with an incredibly fugitive yellow ink. Print collectors will eventually see the same problem in many fine art inkjet prints, maybe not soon, but someday because most of these prints are made with ink sets not nearly as well color balanced for fading over time as the HP inks. This "color balanced" fading of the HP ink set over time can easily be observed in the i* metric data published by AaI&A. I* color and I* tone scores drop evenly as the HP Vivera pigments fade whereas other ink sets show dramatic I* color loss well in advance of much I* tone loss.
Truth be told, I fully realize that most endusers think the print permanence issue has been sufficiently resolved, so none of the vendors, neither OEMs or third party vendors, are under any consumer pressure to improve ink or media permanence these days. Most printmakers believe all you do is just buy any pigment set and your print permanence issues are over.
The role of the yellow ink and the equally important role of media choice are not well understood in the printmaking community, IMHO, in part because most longevity claims are expressed in decades or centuries of "print life" with little or no information given on what the print will actually look like as it ages over time. To put the current state of Inkjet inks and media into perspective from a fine art point of view, consider the lightfastness specification of the United Kinddom's Fine Art Trade Guild for limited edition prints. AaI&A tests show that many pigment printer/ink/media combinations these days won't pass the UK Fine Art trade Guild's Lightfastness requirement that all colors in the finished print be equal or better in lightfastness than the Blue Wool #6 dye.
The UKFATG considers BW#6 (which shows "just noticeable" fade at 100 megalux hours of light exposure), to translate into 100 years of acceptable light fade resistance under typical indoor display conditions. BW #6 fade resistance would thus correlate reasonably with an equivalent AaI&A Conservation Display rating equal to or greater than 100+ Megalux hours, and only the HP Vivera pigment ink set reaches that CDR rating for both color and B&W prints in the AaI&A tests on a fairly wide variety of media. Canon Lucia can achieve the spec, too, but media choice needs to be more selective. Epson Ultrachrome makes it routinely for B&W, but media choice is the most critical factor for Ultrachrome color prints to achieve the UKFATG specification. Epson Ultrachrome HDR gives more safety margin for color prints to meet the spec because the HDR orange ink can be substituted more in skin tone color blends, but RIP/printer driver choice is then a factor as well. BTW, high OBA content in any media usually kills meeting the UKFATG specification no matter what inks you use. I can't give you a comparable Wilhelm rating for BW#6 because WIR tests are conducted to "easily noticeable" not "just noticeable" fading endpoints and are based on densitometry not colorimetry. The Blue Wool scale (consisting of 8 different blue dyes of roughly linear 2-3x increasing lightfade resistance between the dyed wool patches) has only been studied in the museum world using colorimetric measurements, AFAIK. I have never seen Blue Wool data presented in densitometric terms.
cheers,
Mark
http://www.aardenburg-imaging.com
