Digital BW, The Print

Jerry,

The premise of your question is slightly wrong because the light blacks do not shift, nor are they "neutral". I think if you will entertain a long post I will try and explain it clearly.

The issue is not that the light blacks are unstable in K3. To the contrary, the light blacks are very stable which is what induces the problem with color shift in ABW. They are too stable to be used in conjunction with color inks in the making of b&w prints. And the color inks are necessary in order to make the light blacks pleasing to a black & white photographer. Epson black and light blacks are coolish/greenish because Epson cannot provide neutral black/grays in combination of more than two because of patent rights. So, when K2 evolved into K3, its blacks and grays had to be made considerably off-neutral. Epson K3 blacks and grays are measurably greenish. The problem is not the color of the light grays but simply using less stable color inks in combination with stable blacks/grays. That is the core of the problem. A little opposite to your thinking.

In terms of understanding better what "color shift" is I have posted a jpg for you to look at. It is an actual example of color shift in Epson Ultrachrome K3 ABW "sepia toned". This particular ABW print is on Epson Velvet Fine Art Paper which is rated by Epson and by WIR to last more than 400 years before "easily noticeable fade" occurs. It is light stability tested in combination with Piezography CarbonSepia inks. The ABW example and was printed to "look" like CarbonSepia inks for comparison.

http://www.inkjetmall.com/70ML-ABWvsCS.jpg

The above is only a 70 MegaLux dose of exposure which is equivalent to 35 Wilhelm Years or 8 Gallery Exhibition Years. A long time by Tobie standards (he's used them since 2005 and not noticed fade), but a short time by fine photographer standards. Certainly, it is far short of the 400 years rating by Epson and WIR. If you want to read why the Epson and WIR ratings are inaccurate when it comes to color shift in ABW - you can read that in the words of Wilhelm himself rather than depend upon my or other people's opinions. I actually formed my opinions from reading the following small pdfs from Wilhelm's presentations to the Society for Imaging Sciences and Technology. I will warn you that if you are a firm believer in the published Epson longevity ratings, these will be very graphic and possibly disturbing or unsettling. But, I do think it's important to be factually aware of things that may bust your bubble of comfort, especially when the legacy of your work is involved. Better to know this early in your b&w printing than later as you approach the zenith of your years and have no possible chance of reprinting with a more suitable process such as silver, palladium or carbon inkjet.

http://www.wilhelm-research.com/pdf/is_t/WIR_ISTpresen2004_02MMG_HWr.pdf 

and 

http://www.wilhelm-research.com/istar/WIR_IST_2007_09_HW_DS.pdf
 
If you do not wish to read them, the basics are that the WIR testing methods were developed in the age of dye-coupler photography when he could take a densitometer and measure a 60% density patch in each of the cyan, magenta, and yellow dye layers as well as a combined CMY and determine everything there is to know about how dye-coupler photographs fade and color stain. He cites that he can no longer detect color shift in Ultrachrome K3 inks because of that inks complexity. He cites that about 2000 when inkjet moved away from a simple CMYK to light grays and light cyans, light magentas and even more complex agents, he lost the ability to analyze color balance. He argues that a new method designed for him by Mark McCormick-Goodhart (the co-author of the pdfs) but not yet implemented at WIR can detect color balance (something the WIR densitometer is not technically capable of), and that automated and sophisticated spectrophotometers using a CIELab based system of measurements over a much wider array of color patches will be able to measure color balance in colors, neutrals, near-neutrals and flesh tones - which WIR methodology simply cannot detect. WIR gives an example of a gross failure of his system attributed to a simple color print made on a Canon printer. The resulting images however, show what WIR easily noticeable fade looks like. I would argue after reading this that the entire WIR premise of what is easily noticeable is pointed at sunday shooters and scrapbookers rather than fine artists and photographers. These two pdfs will teach you everything you wanted to know about longevity testing as practiced by Epson, Canon and HP which use WIR on an exclusive basis. It's a business model that may not take your best interests into consideration because admittedly it is a system that is not necessarily adapted to inkjet yet, but heavily promotes super-longevity ratings not previously attained by any photographic process.

Afterwards, you may wish to look to this site (http://www.aardenburg-imaging.com/) to begin learning something for yourself about actual longevity testing of modern inksets that are of use to users rather than the tests on the WIR site which appear now to be of more use to OEMs. (I do not mean that to sound condescending) - I mean that its possible to find your answers and to understand why the use of color ink does not promote true longevity in b&w. And to learn and see it visually - from the person that invented the i-Star that WIR presented in the pdfs above. I am using the WIR i-Star beta from the WIR site in conjunction with visible/UV and the target from the WIR site as well as the Aardenburg site. It's am amazing system to be sure. I can even detect OBA fade, something completely missing in WIR tests. 

If you want to learn more about Piezography which is a pure monochrome carbon/modified carbon ink process - we discuss almost exclusively monochromatic inks at http://tech.groups.yahoo.com/group/piezography3000   We do not advise ever to print b&w with color.  Besides printing in considerably higher fidelity than Epson ABW, Piezography has a true fade resistance that ABW does not (when color balance and density are considered both important.) 

Jon Cone
Piezography evangelist and part-time color photography lover.


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Gerald Davey <gdavey@...> wrote:
>
> I'm new to this group but starting to follow this discussion pending  
> some purchase decisions. It seems to me that if there are apparent  
> color shifts even remotely that rapidly in the "neutral" Epson K2 or  
> K3 inks, that it's necessarily the case that there are shifts in the  
> remaining color pigment inks as well. Thus, with the Cone Color inks  
> the statement that they are 100% pigment vs. presumably partial dye  
> content in the Epson inks could be crucial, all else being equal (if  
> it ever is!). Is this consistent with any other's experience?
> 
> Jerry D.
> 
> 
> 
> On Apr 10, 2009, at 10:25 AM, john dean wrote:
> 
> >
> >
> > I've actually seen these Ultrachrome K2 black and white prints  
> > shift within the span of a week in an exhibition where fairly  
> > bright daylight was present. Not ultra bright, but a bit over 450  
> > lux. I'm not kidding and they were framed behind glass. It was a  
> > big embarrassment for the photographer. I'm glad I didn't print  
> > them. But I did spray ALL the Ultrachrome prints I did at that time  
> > with with a uv coating and always used QTR to reduce the color  
> > content. But it is always there to some degree when you are dealing  
> > with brown "gray" inks and trying to achieve neutral color in the  
> > whole range.
> >
> > I have also seen tests I've had around for a few years on a  
> > bulletin board shift, usually toward cyan as the light magenta  
> > goes, or toward blue. No chemicals or pollution in my studio. Of  
> > course these were not behind glass, or sprayed, but to me that  
> > shouldn't be necessary.
> >
> > john
> >
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Jon Cone"  
> > <jon@> wrote:
> > >
> > > David,
> > >
> > > Mayhaps not, but I would not suspect that you would notice any  
> > changes in your work in 5 years. But, it's not black and white like  
> > you are trying to make it either. (pun intended). The threat is  
> > relative to the intent of the photographer and the perceived value  
> > of their work. For others it doesn't really matter two pickles.
> >
> >
> > 
> 
> 
> 
> [Non-text portions of this message have been removed]
>